diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..39a7681
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+/cli/mailfull/mailfull
diff --git a/README.md b/README.md
index 1151d6f..3106b9c 100644
--- a/README.md
+++ b/README.md
@@ -3,4 +3,64 @@ mailfull-go
 
 A management tool for virtual domain email for Postfix and Dovecot written in Go.
 
-**Currently in development.**
+Features
+--------
+
+- You can use both virtual users and system users.
+- Mailfull does not involve in delivery processes of the MTA, is only to generate configuration databases.
+- You do not need to restart Postfix/Dovecot to apply configuration databases.
+- The received email can be passed to the programs.
+
+Installation
+------------
+
+### go get
+
+Installed in `$GOPATH/bin`
+
+```
+$ go get github.com/directorz/mailfull-go/cmd/mailfull
+```
+
+Quick Start
+-----------
+
+Create a new user for Mailfull.
+
+```
+# useradd -r -s /bin/bash mailfull
+# su - mailfull
+```
+
+Initialize a directory as a Mailfull repository.
+
+```
+$ mkdir /path/to/repo && cd /path/to/repo
+$ mailfull init
+```
+
+Generate configurations for Postfix and Dovecot. (Edit as needed.)
+
+```
+$ mailfull genconfig postfix > /etc/postfix/main.cf
+$ mailfull genconfig dovecot > /etc/dovecot/dovecot.conf
+```
+
+Start Postfix and Dovecot.
+
+```
+# systemctl start postfix.service
+# systemctl start dovecot.service
+```
+
+Add a new domain and user.
+
+```
+# cd /path/to/repo
+
+# mailfull domainadd example.com
+# mailfull useradd hoge@example.com
+# mailfull userpasswd hoge@example.com
+```
+
+Enjoy!
diff --git a/aliasdomain.go b/aliasdomain.go
new file mode 100644
index 0000000..b1fc2f7
--- /dev/null
+++ b/aliasdomain.go
@@ -0,0 +1,202 @@
+package mailfull
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+	"path/filepath"
+	"sort"
+	"strings"
+)
+
+// AliasDomain represents a AliasDomain.
+type AliasDomain struct {
+	name   string
+	target string
+}
+
+// AliasDomainSlice attaches the methods of sort.Interface to []*AliasDomain.
+type AliasDomainSlice []*AliasDomain
+
+func (p AliasDomainSlice) Len() int           { return len(p) }
+func (p AliasDomainSlice) Less(i, j int) bool { return p[i].Name() < p[j].Name() }
+func (p AliasDomainSlice) Swap(i, j int)      { p[i], p[j] = p[j], p[i] }
+
+// NewAliasDomain creates a new AliasDomain instance.
+func NewAliasDomain(name, target string) (*AliasDomain, error) {
+	ad := &AliasDomain{}
+
+	if err := ad.setName(name); err != nil {
+		return nil, err
+	}
+
+	if err := ad.SetTarget(target); err != nil {
+		return nil, err
+	}
+
+	return ad, nil
+}
+
+// setName sets the name.
+func (ad *AliasDomain) setName(name string) error {
+	if !validAliasDomainName(name) {
+		return ErrInvalidAliasDomainName
+	}
+
+	ad.name = name
+
+	return nil
+}
+
+// Name returns name.
+func (ad *AliasDomain) Name() string {
+	return ad.name
+}
+
+// SetTarget sets the target.
+func (ad *AliasDomain) SetTarget(target string) error {
+	if !validAliasDomainTarget(target) {
+		return ErrInvalidAliasDomainTarget
+	}
+
+	ad.target = target
+
+	return nil
+}
+
+// Target returns target.
+func (ad *AliasDomain) Target() string {
+	return ad.target
+}
+
+// AliasDomains returns a AliasDomain slice.
+func (r *Repository) AliasDomains() ([]*AliasDomain, error) {
+	file, err := os.Open(filepath.Join(r.DirMailDataPath, FileNameAliasDomains))
+	if err != nil {
+		return nil, err
+	}
+	defer file.Close()
+
+	aliasDomains := make([]*AliasDomain, 0, 10)
+
+	scanner := bufio.NewScanner(file)
+	for scanner.Scan() {
+		words := strings.Split(scanner.Text(), ":")
+		if len(words) != 2 {
+			return nil, ErrInvalidFormatAliasDomain
+		}
+
+		name := words[0]
+		target := words[1]
+
+		aliasDomain, err := NewAliasDomain(name, target)
+		if err != nil {
+			return nil, err
+		}
+
+		aliasDomains = append(aliasDomains, aliasDomain)
+	}
+
+	if err := scanner.Err(); err != nil {
+		return nil, err
+	}
+
+	return aliasDomains, nil
+}
+
+// AliasDomain returns a AliasDomain of the input name.
+func (r *Repository) AliasDomain(aliasDomainName string) (*AliasDomain, error) {
+	aliasDomains, err := r.AliasDomains()
+	if err != nil {
+		return nil, err
+	}
+
+	for _, aliasDomain := range aliasDomains {
+		if aliasDomain.Name() == aliasDomainName {
+			return aliasDomain, nil
+		}
+	}
+
+	return nil, nil
+}
+
+// AliasDomainCreate creates the input AliasDomain.
+func (r *Repository) AliasDomainCreate(aliasDomain *AliasDomain) error {
+	aliasDomains, err := r.AliasDomains()
+	if err != nil {
+		return err
+	}
+
+	for _, ad := range aliasDomains {
+		if ad.Name() == aliasDomain.Name() {
+			return ErrAliasDomainAlreadyExist
+		}
+	}
+	existDomain, err := r.Domain(aliasDomain.Name())
+	if err != nil {
+		return err
+	}
+	if existDomain != nil {
+		return ErrDomainAlreadyExist
+	}
+	existDomain, err = r.Domain(aliasDomain.Target())
+	if err != nil {
+		return err
+	}
+	if existDomain == nil {
+		return ErrDomainNotExist
+	}
+
+	aliasDomains = append(aliasDomains, aliasDomain)
+
+	if err := r.writeAliasDomainsFile(aliasDomains); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// AliasDomainRemove removes a AliasDomain of the input name.
+func (r *Repository) AliasDomainRemove(aliasDomainName string) error {
+	aliasDomains, err := r.AliasDomains()
+	if err != nil {
+		return err
+	}
+
+	idx := -1
+	for i, aliasDomain := range aliasDomains {
+		if aliasDomain.Name() == aliasDomainName {
+			idx = i
+		}
+	}
+	if idx < 0 {
+		return ErrAliasDomainNotExist
+	}
+
+	aliasDomains = append(aliasDomains[:idx], aliasDomains[idx+1:]...)
+
+	if err := r.writeAliasDomainsFile(aliasDomains); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// writeAliasDomainsFile writes a AliasDomain slice to the file.
+func (r *Repository) writeAliasDomainsFile(aliasDomains []*AliasDomain) error {
+	file, err := os.OpenFile(filepath.Join(r.DirMailDataPath, FileNameAliasDomains), os.O_RDWR|os.O_TRUNC, 0600)
+	if err != nil {
+		return err
+	}
+	defer file.Close()
+
+	sort.Sort(AliasDomainSlice(aliasDomains))
+
+	for _, aliasDomain := range aliasDomains {
+		if _, err := fmt.Fprintf(file, "%s:%s\n", aliasDomain.Name(), aliasDomain.Target()); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
diff --git a/aliasuser.go b/aliasuser.go
new file mode 100644
index 0000000..647bcfe
--- /dev/null
+++ b/aliasuser.go
@@ -0,0 +1,245 @@
+package mailfull
+
+import (
+	"bufio"
+	"errors"
+	"fmt"
+	"os"
+	"path/filepath"
+	"sort"
+	"strings"
+)
+
+// Errors for parameter.
+var (
+	ErrNotEnoughAliasUserTargets = errors.New("AliasUser: targets not enough")
+)
+
+// AliasUser represents a AliasUser.
+type AliasUser struct {
+	name    string
+	targets []string
+}
+
+// AliasUserSlice attaches the methods of sort.Interface to []*AliasUser.
+type AliasUserSlice []*AliasUser
+
+func (p AliasUserSlice) Len() int           { return len(p) }
+func (p AliasUserSlice) Less(i, j int) bool { return p[i].Name() < p[j].Name() }
+func (p AliasUserSlice) Swap(i, j int)      { p[i], p[j] = p[j], p[i] }
+
+// NewAliasUser creates a new AliasUser instance.
+func NewAliasUser(name string, targets []string) (*AliasUser, error) {
+	au := &AliasUser{}
+
+	if err := au.setName(name); err != nil {
+		return nil, err
+	}
+
+	if err := au.SetTargets(targets); err != nil {
+		return nil, err
+	}
+
+	return au, nil
+}
+
+// setName sets the name.
+func (au *AliasUser) setName(name string) error {
+	if !validAliasUserName(name) {
+		return ErrInvalidAliasUserName
+	}
+
+	au.name = name
+
+	return nil
+}
+
+// Name returns name.
+func (au *AliasUser) Name() string {
+	return au.name
+}
+
+// SetTargets sets targets.
+func (au *AliasUser) SetTargets(targets []string) error {
+	if len(targets) < 1 {
+		return ErrNotEnoughAliasUserTargets
+	}
+
+	for _, target := range targets {
+		if !validAliasUserTarget(target) {
+			return ErrInvalidAliasUserTarget
+		}
+	}
+
+	au.targets = targets
+
+	return nil
+}
+
+// Targets returns targets.
+func (au *AliasUser) Targets() []string {
+	return au.targets
+}
+
+// AliasUsers returns a AliasUser slice.
+func (r *Repository) AliasUsers(domainName string) ([]*AliasUser, error) {
+	domain, err := r.Domain(domainName)
+	if err != nil {
+		return nil, err
+	}
+	if domain == nil {
+		return nil, ErrDomainNotExist
+	}
+
+	file, err := os.Open(filepath.Join(r.DirMailDataPath, domainName, FileNameAliasUsers))
+	if err != nil {
+		return nil, err
+	}
+	defer file.Close()
+
+	aliasUsers := make([]*AliasUser, 0, 50)
+
+	scanner := bufio.NewScanner(file)
+	for scanner.Scan() {
+		words := strings.Split(scanner.Text(), ":")
+		if len(words) != 2 {
+			return nil, ErrInvalidFormatAliasUsers
+		}
+
+		name := words[0]
+		targets := strings.Split(words[1], ",")
+
+		aliasUser, err := NewAliasUser(name, targets)
+		if err != nil {
+			return nil, err
+		}
+
+		aliasUsers = append(aliasUsers, aliasUser)
+	}
+
+	if err := scanner.Err(); err != nil {
+		return nil, err
+	}
+
+	return aliasUsers, nil
+}
+
+// AliasUser returns a AliasUser of the input name.
+func (r *Repository) AliasUser(domainName, aliasUserName string) (*AliasUser, error) {
+	aliasUsers, err := r.AliasUsers(domainName)
+	if err != nil {
+		return nil, err
+	}
+
+	for _, aliasUser := range aliasUsers {
+		if aliasUser.Name() == aliasUserName {
+			return aliasUser, nil
+		}
+	}
+
+	return nil, nil
+}
+
+// AliasUserCreate creates the input AliasUser.
+func (r *Repository) AliasUserCreate(domainName string, aliasUser *AliasUser) error {
+	aliasUsers, err := r.AliasUsers(domainName)
+	if err != nil {
+		return err
+	}
+
+	for _, au := range aliasUsers {
+		if au.Name() == aliasUser.Name() {
+			return ErrAliasUserAlreadyExist
+		}
+	}
+	existUser, err := r.User(domainName, aliasUser.Name())
+	if err != nil {
+		return err
+	}
+	if existUser != nil {
+		return ErrUserAlreadyExist
+	}
+
+	aliasUsers = append(aliasUsers, aliasUser)
+
+	if err := r.writeAliasUsersFile(domainName, aliasUsers); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// AliasUserUpdate updates the input AliasUser.
+func (r *Repository) AliasUserUpdate(domainName string, aliasUser *AliasUser) error {
+	aliasUsers, err := r.AliasUsers(domainName)
+	if err != nil {
+		return err
+	}
+
+	idx := -1
+	for i, au := range aliasUsers {
+		if au.Name() == aliasUser.Name() {
+			idx = i
+		}
+	}
+	if idx < 0 {
+		return ErrAliasUserNotExist
+	}
+
+	aliasUsers[idx] = aliasUser
+
+	if err := r.writeAliasUsersFile(domainName, aliasUsers); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// AliasUserRemove removes a AliasUser of the input name.
+func (r *Repository) AliasUserRemove(domainName string, aliasUserName string) error {
+	aliasUsers, err := r.AliasUsers(domainName)
+	if err != nil {
+		return err
+	}
+
+	idx := -1
+	for i, aliasUser := range aliasUsers {
+		if aliasUser.Name() == aliasUserName {
+			idx = i
+		}
+	}
+	if idx < 0 {
+		return ErrAliasUserNotExist
+	}
+
+	aliasUsers = append(aliasUsers[:idx], aliasUsers[idx+1:]...)
+
+	if err := r.writeAliasUsersFile(domainName, aliasUsers); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// writeAliasUsersFile writes a AliasUser slice to the file.
+func (r *Repository) writeAliasUsersFile(domainName string, aliasUsers []*AliasUser) error {
+	if !validDomainName(domainName) {
+		return ErrInvalidDomainName
+	}
+
+	file, err := os.OpenFile(filepath.Join(r.DirMailDataPath, domainName, FileNameAliasUsers), os.O_RDWR|os.O_TRUNC, 0600)
+	if err != nil {
+		return err
+	}
+	defer file.Close()
+
+	sort.Sort(AliasUserSlice(aliasUsers))
+
+	for _, aliasUser := range aliasUsers {
+		if _, err := fmt.Fprintf(file, "%s:%s\n", aliasUser.Name(), strings.Join(aliasUser.Targets(), ",")); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
diff --git a/catchalluser.go b/catchalluser.go
new file mode 100644
index 0000000..2853afb
--- /dev/null
+++ b/catchalluser.go
@@ -0,0 +1,110 @@
+package mailfull
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+	"path/filepath"
+)
+
+// CatchAllUser represents a CatchAllUser.
+type CatchAllUser struct {
+	name string
+}
+
+// NewCatchAllUser creates a new CatchAllUser instance.
+func NewCatchAllUser(name string) (*CatchAllUser, error) {
+	if !validCatchAllUserName(name) {
+		return nil, ErrInvalidCatchAllUserName
+	}
+
+	cu := &CatchAllUser{
+		name: name,
+	}
+
+	return cu, nil
+}
+
+// Name returns name.
+func (cu *CatchAllUser) Name() string {
+	return cu.name
+}
+
+// CatchAllUser returns a CatchAllUser that the input name has.
+func (r *Repository) CatchAllUser(domainName string) (*CatchAllUser, error) {
+	domain, err := r.Domain(domainName)
+	if err != nil {
+		return nil, err
+	}
+	if domain == nil {
+		return nil, ErrDomainNotExist
+	}
+
+	file, err := os.Open(filepath.Join(r.DirMailDataPath, domainName, FileNameCatchAllUser))
+	if err != nil {
+		return nil, err
+	}
+	defer file.Close()
+
+	scanner := bufio.NewScanner(file)
+	scanner.Scan()
+
+	name := scanner.Text()
+
+	if err := scanner.Err(); err != nil {
+		return nil, err
+	}
+
+	if name == "" {
+		return nil, nil
+	}
+
+	catchAllUser, err := NewCatchAllUser(name)
+	if err != nil {
+		return nil, err
+	}
+
+	return catchAllUser, nil
+}
+
+// CatchAllUserSet sets a CatchAllUser to the input Domain.
+func (r *Repository) CatchAllUserSet(domainName string, catchAllUser *CatchAllUser) error {
+	existUser, err := r.User(domainName, catchAllUser.Name())
+	if err != nil {
+		return err
+	}
+	if existUser == nil {
+		return ErrUserNotExist
+	}
+
+	file, err := os.OpenFile(filepath.Join(r.DirMailDataPath, domainName, FileNameCatchAllUser), os.O_RDWR|os.O_TRUNC, 0600)
+	if err != nil {
+		return err
+	}
+	defer file.Close()
+
+	if _, err := fmt.Fprintf(file, "%s\n", catchAllUser.Name()); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// CatchAllUserUnset removes a CatchAllUser from the input Domain.
+func (r *Repository) CatchAllUserUnset(domainName string) error {
+	existDomain, err := r.Domain(domainName)
+	if err != nil {
+		return err
+	}
+	if existDomain == nil {
+		return ErrDomainNotExist
+	}
+
+	file, err := os.OpenFile(filepath.Join(r.DirMailDataPath, domainName, FileNameCatchAllUser), os.O_RDWR|os.O_TRUNC, 0600)
+	if err != nil {
+		return err
+	}
+	file.Close()
+
+	return nil
+}
diff --git a/cmd/mailfull/command/aliasdomainadd.go b/cmd/mailfull/command/aliasdomainadd.go
new file mode 100644
index 0000000..41d1222
--- /dev/null
+++ b/cmd/mailfull/command/aliasdomainadd.go
@@ -0,0 +1,80 @@
+package command
+
+import (
+	"fmt"
+
+	mailfull "github.com/directorz/mailfull-go"
+)
+
+// AliasDomainAddCommand represents a AliasDomainAddCommand.
+type AliasDomainAddCommand struct {
+	Meta
+}
+
+// Synopsis returns a one-line synopsis.
+func (c *AliasDomainAddCommand) Synopsis() string {
+	return "Create a new aliasdomain."
+}
+
+// Help returns long-form help text.
+func (c *AliasDomainAddCommand) Help() string {
+	txt := fmt.Sprintf(`
+Usage:
+    %s %s domain target
+
+Description:
+    %s
+
+Required Args:
+    domain
+        The domain name that you want to create.
+    target
+        The target domain name.
+`,
+		c.CmdName, c.SubCmdName,
+		c.Synopsis())
+
+	return txt[1:]
+}
+
+// Run runs the command and returns the exit status.
+func (c *AliasDomainAddCommand) Run(args []string) int {
+	if len(args) != 2 {
+		fmt.Fprintf(c.UI.ErrorWriter, "%v\n", c.Help())
+		return 1
+	}
+
+	aliasDomainName := args[0]
+	targetDomainName := args[1]
+
+	repo, err := mailfull.OpenRepository(".")
+	if err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+
+	aliasDomain, err := mailfull.NewAliasDomain(aliasDomainName, targetDomainName)
+	if err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+
+	if err := repo.AliasDomainCreate(aliasDomain); err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+
+	mailData, err := repo.MailData()
+	if err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+
+	err = repo.GenerateDatabases(mailData)
+	if err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+
+	return 0
+}
diff --git a/cmd/mailfull/command/aliasdomaindel.go b/cmd/mailfull/command/aliasdomaindel.go
new file mode 100644
index 0000000..a16411c
--- /dev/null
+++ b/cmd/mailfull/command/aliasdomaindel.go
@@ -0,0 +1,71 @@
+package command
+
+import (
+	"fmt"
+
+	mailfull "github.com/directorz/mailfull-go"
+)
+
+// AliasDomainDelCommand represents a AliasDomainDelCommand.
+type AliasDomainDelCommand struct {
+	Meta
+}
+
+// Synopsis returns a one-line synopsis.
+func (c *AliasDomainDelCommand) Synopsis() string {
+	return "Delete a aliasdomain."
+}
+
+// Help returns long-form help text.
+func (c *AliasDomainDelCommand) Help() string {
+	txt := fmt.Sprintf(`
+Usage:
+    %s %s domain
+
+Description:
+    %s
+
+Required Args:
+    domain
+        The domain name that you want to delete.
+`,
+		c.CmdName, c.SubCmdName,
+		c.Synopsis())
+
+	return txt[1:]
+}
+
+// Run runs the command and returns the exit status.
+func (c *AliasDomainDelCommand) Run(args []string) int {
+	if len(args) != 1 {
+		fmt.Fprintf(c.UI.ErrorWriter, "%v\n", c.Help())
+		return 1
+	}
+
+	aliasDomainName := args[0]
+
+	repo, err := mailfull.OpenRepository(".")
+	if err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+
+	if err := repo.AliasDomainRemove(aliasDomainName); err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+
+	mailData, err := repo.MailData()
+	if err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+
+	err = repo.GenerateDatabases(mailData)
+	if err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+
+	return 0
+}
diff --git a/cmd/mailfull/command/aliasdomains.go b/cmd/mailfull/command/aliasdomains.go
new file mode 100644
index 0000000..62cbac7
--- /dev/null
+++ b/cmd/mailfull/command/aliasdomains.go
@@ -0,0 +1,75 @@
+package command
+
+import (
+	"fmt"
+	"sort"
+
+	mailfull "github.com/directorz/mailfull-go"
+)
+
+// AliasDomainsCommand represents a AliasDomainsCommand.
+type AliasDomainsCommand struct {
+	Meta
+}
+
+// Synopsis returns a one-line synopsis.
+func (c *AliasDomainsCommand) Synopsis() string {
+	return "Show aliasdomains."
+}
+
+// Help returns long-form help text.
+func (c *AliasDomainsCommand) Help() string {
+	txt := fmt.Sprintf(`
+Usage:
+    %s %s [domain]
+
+Description:
+    %s
+
+Optional Args:
+    domain
+        Show aliasdomains that the target is "domain".
+`,
+		c.CmdName, c.SubCmdName,
+		c.Synopsis())
+
+	return txt[1:]
+}
+
+// Run runs the command and returns the exit status.
+func (c *AliasDomainsCommand) Run(args []string) int {
+	if len(args) > 1 {
+		fmt.Fprintf(c.UI.ErrorWriter, "%v\n", c.Help())
+		return 1
+	}
+
+	targetDomainName := ""
+	if len(args) == 1 {
+		targetDomainName = args[0]
+	}
+
+	repo, err := mailfull.OpenRepository(".")
+	if err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+
+	aliasDomains, err := repo.AliasDomains()
+	if err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+	sort.Sort(mailfull.AliasDomainSlice(aliasDomains))
+
+	for _, aliasDomain := range aliasDomains {
+		if targetDomainName != "" {
+			if aliasDomain.Target() == targetDomainName {
+				fmt.Fprintf(c.UI.Writer, "%s\n", aliasDomain.Name())
+			}
+		} else {
+			fmt.Fprintf(c.UI.Writer, "%s\n", aliasDomain.Name())
+		}
+	}
+
+	return 0
+}
diff --git a/cmd/mailfull/command/aliasuseradd.go b/cmd/mailfull/command/aliasuseradd.go
new file mode 100644
index 0000000..815a01a
--- /dev/null
+++ b/cmd/mailfull/command/aliasuseradd.go
@@ -0,0 +1,89 @@
+package command
+
+import (
+	"fmt"
+	"strings"
+
+	mailfull "github.com/directorz/mailfull-go"
+)
+
+// AliasUserAddCommand represents a AliasUserAddCommand.
+type AliasUserAddCommand struct {
+	Meta
+}
+
+// Synopsis returns a one-line synopsis.
+func (c *AliasUserAddCommand) Synopsis() string {
+	return "Create a new aliasuser."
+}
+
+// Help returns long-form help text.
+func (c *AliasUserAddCommand) Help() string {
+	txt := fmt.Sprintf(`
+Usage:
+    %s %s address target [target...]
+
+Description:
+    %s
+
+Required Args:
+    address
+        The email address that you want to create.
+    target
+        Target email addresses.
+`,
+		c.CmdName, c.SubCmdName,
+		c.Synopsis())
+
+	return txt[1:]
+}
+
+// Run runs the command and returns the exit status.
+func (c *AliasUserAddCommand) Run(args []string) int {
+	if len(args) < 2 {
+		fmt.Fprintf(c.UI.ErrorWriter, "%v\n", c.Help())
+		return 1
+	}
+
+	address := args[0]
+	targets := args[1:]
+
+	words := strings.Split(address, "@")
+	if len(words) != 2 {
+		fmt.Fprintf(c.UI.ErrorWriter, "%v\n", c.Help())
+		return 1
+	}
+	aliasUserName := words[0]
+	domainName := words[1]
+
+	repo, err := mailfull.OpenRepository(".")
+	if err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+
+	aliasUser, err := mailfull.NewAliasUser(aliasUserName, targets)
+	if err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+
+	if err := repo.AliasUserCreate(domainName, aliasUser); err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+
+	mailData, err := repo.MailData()
+	if err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+
+	err = repo.GenerateDatabases(mailData)
+	if err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+
+	return 0
+}
diff --git a/cmd/mailfull/command/aliasuserdel.go b/cmd/mailfull/command/aliasuserdel.go
new file mode 100644
index 0000000..ea519c2
--- /dev/null
+++ b/cmd/mailfull/command/aliasuserdel.go
@@ -0,0 +1,79 @@
+package command
+
+import (
+	"fmt"
+	"strings"
+
+	mailfull "github.com/directorz/mailfull-go"
+)
+
+// AliasUserDelCommand represents a AliasUserDelCommand.
+type AliasUserDelCommand struct {
+	Meta
+}
+
+// Synopsis returns a one-line synopsis.
+func (c *AliasUserDelCommand) Synopsis() string {
+	return "Delete a aliasuser."
+}
+
+// Help returns long-form help text.
+func (c *AliasUserDelCommand) Help() string {
+	txt := fmt.Sprintf(`
+Usage:
+    %s %s address
+
+Description:
+    %s
+
+Required Args:
+    address
+        The email address that you want to delete.
+`,
+		c.CmdName, c.SubCmdName,
+		c.Synopsis())
+
+	return txt[1:]
+}
+
+// Run runs the command and returns the exit status.
+func (c *AliasUserDelCommand) Run(args []string) int {
+	if len(args) != 1 {
+		fmt.Fprintf(c.UI.ErrorWriter, "%v\n", c.Help())
+		return 1
+	}
+
+	address := args[0]
+	words := strings.Split(address, "@")
+	if len(words) != 2 {
+		fmt.Fprintf(c.UI.ErrorWriter, "%v\n", c.Help())
+		return 1
+	}
+	aliasUserName := words[0]
+	domainName := words[1]
+
+	repo, err := mailfull.OpenRepository(".")
+	if err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+
+	if err := repo.AliasUserRemove(domainName, aliasUserName); err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+
+	mailData, err := repo.MailData()
+	if err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+
+	err = repo.GenerateDatabases(mailData)
+	if err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+
+	return 0
+}
diff --git a/cmd/mailfull/command/aliasusermod.go b/cmd/mailfull/command/aliasusermod.go
new file mode 100644
index 0000000..16763fe
--- /dev/null
+++ b/cmd/mailfull/command/aliasusermod.go
@@ -0,0 +1,98 @@
+package command
+
+import (
+	"fmt"
+	"strings"
+
+	mailfull "github.com/directorz/mailfull-go"
+)
+
+// AliasUserModCommand represents a AliasUserModCommand.
+type AliasUserModCommand struct {
+	Meta
+}
+
+// Synopsis returns a one-line synopsis.
+func (c *AliasUserModCommand) Synopsis() string {
+	return "Modify a aliasuser."
+}
+
+// Help returns long-form help text.
+func (c *AliasUserModCommand) Help() string {
+	txt := fmt.Sprintf(`
+Usage:
+    %s %s address target [target...]
+
+Description:
+    %s
+
+Required Args:
+    address
+        The email address that you want to modify.
+    target
+        Target email addresses.
+`,
+		c.CmdName, c.SubCmdName,
+		c.Synopsis())
+
+	return txt[1:]
+}
+
+// Run runs the command and returns the exit status.
+func (c *AliasUserModCommand) Run(args []string) int {
+	if len(args) < 2 {
+		fmt.Fprintf(c.UI.ErrorWriter, "%v\n", c.Help())
+		return 1
+	}
+
+	address := args[0]
+	targets := args[1:]
+
+	words := strings.Split(address, "@")
+	if len(words) != 2 {
+		fmt.Fprintf(c.UI.ErrorWriter, "%v\n", c.Help())
+		return 1
+	}
+	aliasUserName := words[0]
+	domainName := words[1]
+
+	repo, err := mailfull.OpenRepository(".")
+	if err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+
+	aliasUser, err := repo.AliasUser(domainName, aliasUserName)
+	if err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+	if aliasUser == nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", mailfull.ErrAliasUserNotExist)
+		return 1
+	}
+
+	if err := aliasUser.SetTargets(targets); err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+
+	if err := repo.AliasUserUpdate(domainName, aliasUser); err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+
+	mailData, err := repo.MailData()
+	if err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+
+	err = repo.GenerateDatabases(mailData)
+	if err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+
+	return 0
+}
diff --git a/cmd/mailfull/command/aliasusers.go b/cmd/mailfull/command/aliasusers.go
new file mode 100644
index 0000000..036b23a
--- /dev/null
+++ b/cmd/mailfull/command/aliasusers.go
@@ -0,0 +1,66 @@
+package command
+
+import (
+	"fmt"
+	"sort"
+
+	"github.com/directorz/mailfull-go"
+)
+
+// AliasUsersCommand represents a AliasUsersCommand.
+type AliasUsersCommand struct {
+	Meta
+}
+
+// Synopsis returns a one-line synopsis.
+func (c *AliasUsersCommand) Synopsis() string {
+	return "Show aliasusers."
+}
+
+// Help returns long-form help text.
+func (c *AliasUsersCommand) Help() string {
+	txt := fmt.Sprintf(`
+Usage:
+    %s %s domain
+
+Description:
+    %s
+
+Required Args:
+    domain
+        The domain name.
+`,
+		c.CmdName, c.SubCmdName,
+		c.Synopsis())
+
+	return txt[1:]
+}
+
+// Run runs the command and returns the exit status.
+func (c *AliasUsersCommand) Run(args []string) int {
+	if len(args) != 1 {
+		fmt.Fprintf(c.UI.ErrorWriter, "%v\n", c.Help())
+		return 1
+	}
+
+	targetDomainName := args[0]
+
+	repo, err := mailfull.OpenRepository(".")
+	if err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+
+	aliasUsers, err := repo.AliasUsers(targetDomainName)
+	if err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+	sort.Sort(mailfull.AliasUserSlice(aliasUsers))
+
+	for _, aliasUser := range aliasUsers {
+		fmt.Fprintf(c.UI.Writer, "%s\n", aliasUser.Name())
+	}
+
+	return 0
+}
diff --git a/cmd/mailfull/command/catchall.go b/cmd/mailfull/command/catchall.go
new file mode 100644
index 0000000..3c1db48
--- /dev/null
+++ b/cmd/mailfull/command/catchall.go
@@ -0,0 +1,64 @@
+package command
+
+import (
+	"fmt"
+
+	"github.com/directorz/mailfull-go"
+)
+
+// CatchAllCommand represents a CatchAllCommand.
+type CatchAllCommand struct {
+	Meta
+}
+
+// Synopsis returns a one-line synopsis.
+func (c *CatchAllCommand) Synopsis() string {
+	return "Show a catchall user."
+}
+
+// Help returns long-form help text.
+func (c *CatchAllCommand) Help() string {
+	txt := fmt.Sprintf(`
+Usage:
+    %s %s domain
+
+Description:
+    %s
+
+Required Args:
+    domain
+        The domain name.
+`,
+		c.CmdName, c.SubCmdName,
+		c.Synopsis())
+
+	return txt[1:]
+}
+
+// Run runs the command and returns the exit status.
+func (c *CatchAllCommand) Run(args []string) int {
+	if len(args) != 1 {
+		fmt.Fprintf(c.UI.ErrorWriter, "%v\n", c.Help())
+		return 1
+	}
+
+	domainName := args[0]
+
+	repo, err := mailfull.OpenRepository(".")
+	if err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+
+	catchAllUser, err := repo.CatchAllUser(domainName)
+	if err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+
+	if catchAllUser != nil {
+		fmt.Fprintf(c.UI.Writer, "%s\n", catchAllUser.Name())
+	}
+
+	return 0
+}
diff --git a/cmd/mailfull/command/catchallset.go b/cmd/mailfull/command/catchallset.go
new file mode 100644
index 0000000..c7fa893
--- /dev/null
+++ b/cmd/mailfull/command/catchallset.go
@@ -0,0 +1,80 @@
+package command
+
+import (
+	"fmt"
+
+	"github.com/directorz/mailfull-go"
+)
+
+// CatchAllSetCommand represents a CatchAllSetCommand.
+type CatchAllSetCommand struct {
+	Meta
+}
+
+// Synopsis returns a one-line synopsis.
+func (c *CatchAllSetCommand) Synopsis() string {
+	return "Set a catchall user."
+}
+
+// Help returns long-form help text.
+func (c *CatchAllSetCommand) Help() string {
+	txt := fmt.Sprintf(`
+Usage:
+    %s %s domain user
+
+Description:
+    %s
+
+Required Args:
+    domain
+        The domain name.
+    user
+        The user name that you want to set as catchall user.
+`,
+		c.CmdName, c.SubCmdName,
+		c.Synopsis())
+
+	return txt[1:]
+}
+
+// Run runs the command and returns the exit status.
+func (c *CatchAllSetCommand) Run(args []string) int {
+	if len(args) != 2 {
+		fmt.Fprintf(c.UI.ErrorWriter, "%v\n", c.Help())
+		return 1
+	}
+
+	domainName := args[0]
+	userName := args[1]
+
+	repo, err := mailfull.OpenRepository(".")
+	if err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+
+	catchAllUser, err := mailfull.NewCatchAllUser(userName)
+	if err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+
+	if err := repo.CatchAllUserSet(domainName, catchAllUser); err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+
+	mailData, err := repo.MailData()
+	if err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+
+	err = repo.GenerateDatabases(mailData)
+	if err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+
+	return 0
+}
diff --git a/cmd/mailfull/command/catchallunset.go b/cmd/mailfull/command/catchallunset.go
new file mode 100644
index 0000000..bf4164a
--- /dev/null
+++ b/cmd/mailfull/command/catchallunset.go
@@ -0,0 +1,71 @@
+package command
+
+import (
+	"fmt"
+
+	"github.com/directorz/mailfull-go"
+)
+
+// CatchAllUnsetCommand represents a CatchAllUnsetCommand.
+type CatchAllUnsetCommand struct {
+	Meta
+}
+
+// Synopsis returns a one-line synopsis.
+func (c *CatchAllUnsetCommand) Synopsis() string {
+	return "Unset a catchall user."
+}
+
+// Help returns long-form help text.
+func (c *CatchAllUnsetCommand) Help() string {
+	txt := fmt.Sprintf(`
+Usage:
+    %s %s domain
+
+Description:
+    %s
+
+Required Args:
+    domain
+        The domain name.
+`,
+		c.CmdName, c.SubCmdName,
+		c.Synopsis())
+
+	return txt[1:]
+}
+
+// Run runs the command and returns the exit status.
+func (c *CatchAllUnsetCommand) Run(args []string) int {
+	if len(args) != 1 {
+		fmt.Fprintf(c.UI.ErrorWriter, "%v\n", c.Help())
+		return 1
+	}
+
+	domainName := args[0]
+
+	repo, err := mailfull.OpenRepository(".")
+	if err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+
+	if err := repo.CatchAllUserUnset(domainName); err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+
+	mailData, err := repo.MailData()
+	if err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+
+	err = repo.GenerateDatabases(mailData)
+	if err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+
+	return 0
+}
diff --git a/cmd/mailfull/command/commit.go b/cmd/mailfull/command/commit.go
new file mode 100644
index 0000000..790b071
--- /dev/null
+++ b/cmd/mailfull/command/commit.go
@@ -0,0 +1,55 @@
+package command
+
+import (
+	"fmt"
+
+	"github.com/directorz/mailfull-go"
+)
+
+// CommitCommand represents a CommitCommand.
+type CommitCommand struct {
+	Meta
+}
+
+// Synopsis returns a one-line synopsis.
+func (c *CommitCommand) Synopsis() string {
+	return "Create databases from the structure of the MailData directory."
+}
+
+// Help returns long-form help text.
+func (c *CommitCommand) Help() string {
+	txt := fmt.Sprintf(`
+Usage:
+    %s %s
+
+Description:
+    %s
+`,
+		c.CmdName, c.SubCmdName,
+		c.Synopsis())
+
+	return txt[1:]
+}
+
+// Run runs the command and returns the exit status.
+func (c *CommitCommand) Run(args []string) int {
+	repo, err := mailfull.OpenRepository(".")
+	if err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+
+	mailData, err := repo.MailData()
+	if err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+
+	err = repo.GenerateDatabases(mailData)
+	if err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+
+	return 0
+}
diff --git a/cmd/mailfull/command/domainadd.go b/cmd/mailfull/command/domainadd.go
new file mode 100644
index 0000000..6e04fb2
--- /dev/null
+++ b/cmd/mailfull/command/domainadd.go
@@ -0,0 +1,88 @@
+package command
+
+import (
+	"fmt"
+
+	"github.com/directorz/mailfull-go"
+)
+
+// DomainAddCommand represents a DomainAddCommand.
+type DomainAddCommand struct {
+	Meta
+}
+
+// Synopsis returns a one-line synopsis.
+func (c *DomainAddCommand) Synopsis() string {
+	return "Create a new domain and postmaster."
+}
+
+// Help returns long-form help text.
+func (c *DomainAddCommand) Help() string {
+	txt := fmt.Sprintf(`
+Usage:
+    %s %s domain
+
+Description:
+    %s
+
+Required Args:
+    domain
+        The domain name that you want to create.
+`,
+		c.CmdName, c.SubCmdName,
+		c.Synopsis())
+
+	return txt[1:]
+}
+
+// Run runs the command and returns the exit status.
+func (c *DomainAddCommand) Run(args []string) int {
+	if len(args) != 1 {
+		fmt.Fprintf(c.UI.ErrorWriter, "%v\n", c.Help())
+		return 1
+	}
+
+	domainName := args[0]
+
+	repo, err := mailfull.OpenRepository(".")
+	if err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+
+	domain, err := mailfull.NewDomain(domainName)
+	if err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+
+	if err := repo.DomainCreate(domain); err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+
+	user, err := mailfull.NewUser("postmaster", mailfull.NeverMatchHashedPassword, nil)
+	if err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+
+	if err := repo.UserCreate(domainName, user); err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+
+	mailData, err := repo.MailData()
+	if err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+
+	err = repo.GenerateDatabases(mailData)
+	if err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+
+	return 0
+}
diff --git a/cmd/mailfull/command/domaindel.go b/cmd/mailfull/command/domaindel.go
new file mode 100644
index 0000000..e7dcee7
--- /dev/null
+++ b/cmd/mailfull/command/domaindel.go
@@ -0,0 +1,71 @@
+package command
+
+import (
+	"fmt"
+
+	"github.com/directorz/mailfull-go"
+)
+
+// DomainDelCommand represents a DomainDelCommand.
+type DomainDelCommand struct {
+	Meta
+}
+
+// Synopsis returns a one-line synopsis.
+func (c *DomainDelCommand) Synopsis() string {
+	return "Delete and backup a domain."
+}
+
+// Help returns long-form help text.
+func (c *DomainDelCommand) Help() string {
+	txt := fmt.Sprintf(`
+Usage:
+    %s %s domain
+
+Description:
+    %s
+
+Required Args:
+    domain
+        The domain name that you want to delete.
+`,
+		c.CmdName, c.SubCmdName,
+		c.Synopsis())
+
+	return txt[1:]
+}
+
+// Run runs the command and returns the exit status.
+func (c *DomainDelCommand) Run(args []string) int {
+	if len(args) != 1 {
+		fmt.Fprintf(c.UI.ErrorWriter, "%v\n", c.Help())
+		return 1
+	}
+
+	domainName := args[0]
+
+	repo, err := mailfull.OpenRepository(".")
+	if err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+
+	if err := repo.DomainRemove(domainName); err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+
+	mailData, err := repo.MailData()
+	if err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+
+	err = repo.GenerateDatabases(mailData)
+	if err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+
+	return 0
+}
diff --git a/cmd/mailfull/command/domains.go b/cmd/mailfull/command/domains.go
new file mode 100644
index 0000000..3d7f197
--- /dev/null
+++ b/cmd/mailfull/command/domains.go
@@ -0,0 +1,55 @@
+package command
+
+import (
+	"fmt"
+	"sort"
+
+	"github.com/directorz/mailfull-go"
+)
+
+// DomainsCommand represents a DomainsCommand.
+type DomainsCommand struct {
+	Meta
+}
+
+// Synopsis returns a one-line synopsis.
+func (c *DomainsCommand) Synopsis() string {
+	return "Show domains."
+}
+
+// Help returns long-form help text.
+func (c *DomainsCommand) Help() string {
+	txt := fmt.Sprintf(`
+Usage:
+    %s %s
+
+Description:
+    %s
+`,
+		c.CmdName, c.SubCmdName,
+		c.Synopsis())
+
+	return txt[1:]
+}
+
+// Run runs the command and returns the exit status.
+func (c *DomainsCommand) Run(args []string) int {
+	repo, err := mailfull.OpenRepository(".")
+	if err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+
+	domains, err := repo.Domains()
+	if err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+	sort.Sort(mailfull.DomainSlice(domains))
+
+	for _, domain := range domains {
+		fmt.Fprintf(c.UI.Writer, "%s\n", domain.Name())
+	}
+
+	return 0
+}
diff --git a/cmd/mailfull/command/genconfig.go b/cmd/mailfull/command/genconfig.go
new file mode 100644
index 0000000..e2a4b27
--- /dev/null
+++ b/cmd/mailfull/command/genconfig.go
@@ -0,0 +1,67 @@
+package command
+
+import (
+	"fmt"
+
+	"github.com/directorz/mailfull-go"
+)
+
+// GenConfigCommand represents a GenConfigCommand.
+type GenConfigCommand struct {
+	Meta
+}
+
+// Synopsis returns a one-line synopsis.
+func (c *GenConfigCommand) Synopsis() string {
+	return "Write a Postfix or Dovecot configuration to stdout."
+}
+
+// Help returns long-form help text.
+func (c *GenConfigCommand) Help() string {
+	txt := fmt.Sprintf(`
+Usage:
+    %s %s name
+
+Description:
+    %s
+
+Required Args:
+    name
+        The software name that you want to generate a configuration.
+        Available names are "postfix" and "dovecot".
+`,
+		c.CmdName, c.SubCmdName,
+		c.Synopsis())
+
+	return txt[1:]
+}
+
+// Run runs the command and returns the exit status.
+func (c *GenConfigCommand) Run(args []string) int {
+	if len(args) != 1 {
+		fmt.Fprintf(c.UI.ErrorWriter, "%v\n", c.Help())
+		return 1
+	}
+
+	softwareName := args[0]
+
+	repo, err := mailfull.OpenRepository(".")
+	if err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+
+	switch softwareName {
+	case "postfix":
+		fmt.Fprintf(c.UI.Writer, "%s", repo.GenerateConfigPostfix())
+
+	case "dovecot":
+		fmt.Fprintf(c.UI.Writer, "%s", repo.GenerateConfigDovecot())
+
+	default:
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] Specify \"postfix\" or \"dovecot\".\n")
+		return 1
+	}
+
+	return 0
+}
diff --git a/cmd/mailfull/command/init.go b/cmd/mailfull/command/init.go
new file mode 100644
index 0000000..b915c7c
--- /dev/null
+++ b/cmd/mailfull/command/init.go
@@ -0,0 +1,42 @@
+package command
+
+import (
+	"fmt"
+
+	"github.com/directorz/mailfull-go"
+)
+
+// InitCommand represents a InitCommand.
+type InitCommand struct {
+	Meta
+}
+
+// Synopsis returns a one-line synopsis.
+func (c *InitCommand) Synopsis() string {
+	return "Initializes current directory as a Mailfull repository."
+}
+
+// Help returns long-form help text.
+func (c *InitCommand) Help() string {
+	txt := fmt.Sprintf(`
+Usage:
+    %s %s
+
+Description:
+    %s
+`,
+		c.CmdName, c.SubCmdName,
+		c.Synopsis())
+
+	return txt[1:]
+}
+
+// Run runs the command and returns the exit status.
+func (c *InitCommand) Run(args []string) int {
+	if err := mailfull.InitRepository("."); err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+
+	return 0
+}
diff --git a/cmd/mailfull/command/main.go b/cmd/mailfull/command/main.go
new file mode 100644
index 0000000..041cf7a
--- /dev/null
+++ b/cmd/mailfull/command/main.go
@@ -0,0 +1,13 @@
+package command
+
+import (
+	"github.com/mitchellh/cli"
+)
+
+// Meta is for `*Command` struct.
+type Meta struct {
+	UI         *cli.BasicUi
+	CmdName    string
+	SubCmdName string
+	Version    string
+}
diff --git a/cmd/mailfull/command/useradd.go b/cmd/mailfull/command/useradd.go
new file mode 100644
index 0000000..8f3bd1f
--- /dev/null
+++ b/cmd/mailfull/command/useradd.go
@@ -0,0 +1,86 @@
+package command
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/directorz/mailfull-go"
+)
+
+// UserAddCommand represents a UserAddCommand.
+type UserAddCommand struct {
+	Meta
+}
+
+// Synopsis returns a one-line synopsis.
+func (c *UserAddCommand) Synopsis() string {
+	return "Create a new user."
+}
+
+// Help returns long-form help text.
+func (c *UserAddCommand) Help() string {
+	txt := fmt.Sprintf(`
+Usage:
+    %s %s address
+
+Description:
+    %s
+
+Required Args:
+    address
+        The email address that you want to create.
+`,
+		c.CmdName, c.SubCmdName,
+		c.Synopsis())
+
+	return txt[1:]
+}
+
+// Run runs the command and returns the exit status.
+func (c *UserAddCommand) Run(args []string) int {
+	if len(args) != 1 {
+		fmt.Fprintf(c.UI.ErrorWriter, "%v\n", c.Help())
+		return 1
+	}
+
+	address := args[0]
+	words := strings.Split(address, "@")
+	if len(words) != 2 {
+		fmt.Fprintf(c.UI.ErrorWriter, "%v\n", c.Help())
+		return 1
+	}
+
+	userName := words[0]
+	domainName := words[1]
+
+	repo, err := mailfull.OpenRepository(".")
+	if err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+
+	user, err := mailfull.NewUser(userName, mailfull.NeverMatchHashedPassword, nil)
+	if err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+
+	if err := repo.UserCreate(domainName, user); err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+
+	mailData, err := repo.MailData()
+	if err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+
+	err = repo.GenerateDatabases(mailData)
+	if err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+
+	return 0
+}
diff --git a/cmd/mailfull/command/usercheckpw.go b/cmd/mailfull/command/usercheckpw.go
new file mode 100644
index 0000000..6fd8e37
--- /dev/null
+++ b/cmd/mailfull/command/usercheckpw.go
@@ -0,0 +1,100 @@
+package command
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/directorz/mailfull-go"
+	"github.com/jsimonetti/pwscheme/ssha"
+)
+
+// UserCheckPwCommand represents a UserCheckPwCommand.
+type UserCheckPwCommand struct {
+	Meta
+}
+
+// Synopsis returns a one-line synopsis.
+func (c *UserCheckPwCommand) Synopsis() string {
+	return "Check user's password."
+}
+
+// Help returns long-form help text.
+func (c *UserCheckPwCommand) Help() string {
+	txt := fmt.Sprintf(`
+Usage:
+    %s %s address [password]
+
+Description:
+    %s
+
+Required Args:
+    address
+        The email address that you want to check the password.
+
+Optional Args:
+    password
+        Specify the password instead of your typing.
+        This option is not recommended because the password will be visible in your shell history.
+`,
+		c.CmdName, c.SubCmdName,
+		c.Synopsis())
+
+	return txt[1:]
+}
+
+// Run runs the command and returns the exit status.
+func (c *UserCheckPwCommand) Run(args []string) int {
+	if len(args) != 1 && len(args) != 2 {
+		fmt.Fprintf(c.UI.ErrorWriter, "%v\n", c.Help())
+		return 1
+	}
+
+	address := args[0]
+	words := strings.Split(address, "@")
+	if len(words) != 2 {
+		fmt.Fprintf(c.UI.ErrorWriter, "%v\n", c.Help())
+		return 1
+	}
+
+	userName := words[0]
+	domainName := words[1]
+
+	rawPassword := ""
+	if len(args) == 2 {
+		rawPassword = args[1]
+	}
+
+	repo, err := mailfull.OpenRepository(".")
+	if err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+
+	user, err := repo.User(domainName, userName)
+	if err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+	if user == nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", mailfull.ErrUserNotExist)
+		return 1
+	}
+
+	if len(args) != 2 {
+		input, err1 := c.UI.AskSecret(fmt.Sprintf("Enter password for %s:", address))
+		if err1 != nil {
+			fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err1)
+			return 1
+		}
+
+		rawPassword = input
+	}
+
+	if ok, _ := ssha.Validate(rawPassword, user.HashedPassword()); !ok {
+		fmt.Fprintf(c.UI.Writer, "The password you entered is incorrect.\n")
+		return 1
+	}
+
+	fmt.Fprintf(c.UI.Writer, "The password you entered is correct.\n")
+	return 0
+}
diff --git a/cmd/mailfull/command/userdel.go b/cmd/mailfull/command/userdel.go
new file mode 100644
index 0000000..b19c365
--- /dev/null
+++ b/cmd/mailfull/command/userdel.go
@@ -0,0 +1,80 @@
+package command
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/directorz/mailfull-go"
+)
+
+// UserDelCommand represents a UserDelCommand.
+type UserDelCommand struct {
+	Meta
+}
+
+// Synopsis returns a one-line synopsis.
+func (c *UserDelCommand) Synopsis() string {
+	return "Delete and backup a user."
+}
+
+// Help returns long-form help text.
+func (c *UserDelCommand) Help() string {
+	txt := fmt.Sprintf(`
+Usage:
+    %s %s address
+
+Description:
+    %s
+
+Required Args:
+    address
+        The email address that you want to delete.
+`,
+		c.CmdName, c.SubCmdName,
+		c.Synopsis())
+
+	return txt[1:]
+}
+
+// Run runs the command and returns the exit status.
+func (c *UserDelCommand) Run(args []string) int {
+	if len(args) != 1 {
+		fmt.Fprintf(c.UI.ErrorWriter, "%v\n", c.Help())
+		return 1
+	}
+
+	address := args[0]
+	words := strings.Split(address, "@")
+	if len(words) != 2 {
+		fmt.Fprintf(c.UI.ErrorWriter, "%v\n", c.Help())
+		return 1
+	}
+
+	userName := words[0]
+	domainName := words[1]
+
+	repo, err := mailfull.OpenRepository(".")
+	if err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+
+	if err := repo.UserRemove(domainName, userName); err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+
+	mailData, err := repo.MailData()
+	if err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+
+	err = repo.GenerateDatabases(mailData)
+	if err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+
+	return 0
+}
diff --git a/cmd/mailfull/command/userpasswd.go b/cmd/mailfull/command/userpasswd.go
new file mode 100644
index 0000000..5f5be57
--- /dev/null
+++ b/cmd/mailfull/command/userpasswd.go
@@ -0,0 +1,131 @@
+package command
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/directorz/mailfull-go"
+	"github.com/jsimonetti/pwscheme/ssha"
+)
+
+// UserPasswdCommand represents a UserPasswdCommand.
+type UserPasswdCommand struct {
+	Meta
+}
+
+// Synopsis returns a one-line synopsis.
+func (c *UserPasswdCommand) Synopsis() string {
+	return "Update user's password."
+}
+
+// Help returns long-form help text.
+func (c *UserPasswdCommand) Help() string {
+	txt := fmt.Sprintf(`
+Usage:
+    %s %s address [password]
+
+Description:
+    %s
+
+Required Args:
+    address
+        The email address that you want to update the password.
+
+Optional Args:
+    password
+        Specify the password instead of your typing.
+        This option is not recommended because the password will be visible in your shell history.
+`,
+		c.CmdName, c.SubCmdName,
+		c.Synopsis())
+
+	return txt[1:]
+}
+
+// Run runs the command and returns the exit status.
+func (c *UserPasswdCommand) Run(args []string) int {
+	if len(args) != 1 && len(args) != 2 {
+		fmt.Fprintf(c.UI.ErrorWriter, "%v\n", c.Help())
+		return 1
+	}
+
+	address := args[0]
+	words := strings.Split(address, "@")
+	if len(words) != 2 {
+		fmt.Fprintf(c.UI.ErrorWriter, "%v\n", c.Help())
+		return 1
+	}
+
+	userName := words[0]
+	domainName := words[1]
+
+	rawPassword := ""
+	if len(args) == 2 {
+		rawPassword = args[1]
+	}
+
+	repo, err := mailfull.OpenRepository(".")
+	if err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+
+	user, err := repo.User(domainName, userName)
+	if err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+	if user == nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", mailfull.ErrUserNotExist)
+		return 1
+	}
+
+	if len(args) != 2 {
+		input1, err1 := c.UI.AskSecret(fmt.Sprintf("Enter new password for %s:", address))
+		if err1 != nil {
+			fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err1)
+			return 1
+		}
+		input2, err2 := c.UI.AskSecret("Retype new password:")
+		if err2 != nil {
+			fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err2)
+			return 1
+		}
+		if input1 != input2 {
+			fmt.Fprintf(c.UI.ErrorWriter, "[ERR] inputs do not match.\n")
+			return 1
+		}
+		rawPassword = input1
+	}
+
+	hashedPassword := mailfull.NeverMatchHashedPassword
+	if rawPassword != "" {
+		str, errHash := ssha.Generate(rawPassword, 4)
+		if errHash != nil {
+			fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", errHash)
+			return 1
+		}
+		hashedPassword = str
+	}
+
+	user.SetHashedPassword(hashedPassword)
+
+	if err := repo.UserUpdate(domainName, user); err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+
+	mailData, err := repo.MailData()
+	if err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+
+	err = repo.GenerateDatabases(mailData)
+	if err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+
+	return 0
+}
diff --git a/cmd/mailfull/command/users.go b/cmd/mailfull/command/users.go
new file mode 100644
index 0000000..2f5038d
--- /dev/null
+++ b/cmd/mailfull/command/users.go
@@ -0,0 +1,66 @@
+package command
+
+import (
+	"fmt"
+	"sort"
+
+	"github.com/directorz/mailfull-go"
+)
+
+// UsersCommand represents a UsersCommand.
+type UsersCommand struct {
+	Meta
+}
+
+// Synopsis returns a one-line synopsis.
+func (c *UsersCommand) Synopsis() string {
+	return "Show users."
+}
+
+// Help returns long-form help text.
+func (c *UsersCommand) Help() string {
+	txt := fmt.Sprintf(`
+Usage:
+    %s %s domain
+
+Description:
+    %s
+
+Required Args:
+    domain
+        The domain name.
+`,
+		c.CmdName, c.SubCmdName,
+		c.Synopsis())
+
+	return txt[1:]
+}
+
+// Run runs the command and returns the exit status.
+func (c *UsersCommand) Run(args []string) int {
+	if len(args) != 1 {
+		fmt.Fprintf(c.UI.ErrorWriter, "%v\n", c.Help())
+		return 1
+	}
+
+	targetDomainName := args[0]
+
+	repo, err := mailfull.OpenRepository(".")
+	if err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+
+	users, err := repo.Users(targetDomainName)
+	if err != nil {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
+		return 1
+	}
+	sort.Sort(mailfull.UserSlice(users))
+
+	for _, user := range users {
+		fmt.Fprintf(c.UI.Writer, "%s\n", user.Name())
+	}
+
+	return 0
+}
diff --git a/cmd/mailfull/main.go b/cmd/mailfull/main.go
new file mode 100644
index 0000000..83154d7
--- /dev/null
+++ b/cmd/mailfull/main.go
@@ -0,0 +1,137 @@
+/*
+Command mailfull is a CLI application using the mailfull package.
+*/
+package main
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+
+	"github.com/directorz/mailfull-go"
+	"github.com/directorz/mailfull-go/cmd/mailfull/command"
+	"github.com/mitchellh/cli"
+)
+
+var (
+	version = mailfull.Version
+	gittag  = ""
+)
+
+func init() {
+	if gittag != "" {
+		version = version + "-" + gittag
+	}
+}
+
+func main() {
+	c := &cli.CLI{
+		Name:    filepath.Base(os.Args[0]),
+		Version: version,
+		Args:    os.Args[1:],
+	}
+
+	meta := command.Meta{
+		UI: &cli.BasicUi{
+			Reader:      os.Stdin,
+			Writer:      os.Stdout,
+			ErrorWriter: os.Stderr,
+		},
+		CmdName: c.Name,
+		Version: c.Version,
+	}
+
+	c.Commands = map[string]cli.CommandFactory{
+		"init": func() (cli.Command, error) {
+			meta.SubCmdName = c.Subcommand()
+			return &command.InitCommand{Meta: meta}, nil
+		},
+		"genconfig": func() (cli.Command, error) {
+			meta.SubCmdName = c.Subcommand()
+			return &command.GenConfigCommand{Meta: meta}, nil
+		},
+		"domains": func() (cli.Command, error) {
+			meta.SubCmdName = c.Subcommand()
+			return &command.DomainsCommand{Meta: meta}, nil
+		},
+		"domainadd": func() (cli.Command, error) {
+			meta.SubCmdName = c.Subcommand()
+			return &command.DomainAddCommand{Meta: meta}, nil
+		},
+		"domaindel": func() (cli.Command, error) {
+			meta.SubCmdName = c.Subcommand()
+			return &command.DomainDelCommand{Meta: meta}, nil
+		},
+		"aliasdomains": func() (cli.Command, error) {
+			meta.SubCmdName = c.Subcommand()
+			return &command.AliasDomainsCommand{Meta: meta}, nil
+		},
+		"aliasdomainadd": func() (cli.Command, error) {
+			meta.SubCmdName = c.Subcommand()
+			return &command.AliasDomainAddCommand{Meta: meta}, nil
+		},
+		"aliasdomaindel": func() (cli.Command, error) {
+			meta.SubCmdName = c.Subcommand()
+			return &command.AliasDomainDelCommand{Meta: meta}, nil
+		},
+		"users": func() (cli.Command, error) {
+			meta.SubCmdName = c.Subcommand()
+			return &command.UsersCommand{Meta: meta}, nil
+		},
+		"useradd": func() (cli.Command, error) {
+			meta.SubCmdName = c.Subcommand()
+			return &command.UserAddCommand{Meta: meta}, nil
+		},
+		"userdel": func() (cli.Command, error) {
+			meta.SubCmdName = c.Subcommand()
+			return &command.UserDelCommand{Meta: meta}, nil
+		},
+		"userpasswd": func() (cli.Command, error) {
+			meta.SubCmdName = c.Subcommand()
+			return &command.UserPasswdCommand{Meta: meta}, nil
+		},
+		"usercheckpw": func() (cli.Command, error) {
+			meta.SubCmdName = c.Subcommand()
+			return &command.UserCheckPwCommand{Meta: meta}, nil
+		},
+		"aliasusers": func() (cli.Command, error) {
+			meta.SubCmdName = c.Subcommand()
+			return &command.AliasUsersCommand{Meta: meta}, nil
+		},
+		"aliasuseradd": func() (cli.Command, error) {
+			meta.SubCmdName = c.Subcommand()
+			return &command.AliasUserAddCommand{Meta: meta}, nil
+		},
+		"aliasusermod": func() (cli.Command, error) {
+			meta.SubCmdName = c.Subcommand()
+			return &command.AliasUserModCommand{Meta: meta}, nil
+		},
+		"aliasuserdel": func() (cli.Command, error) {
+			meta.SubCmdName = c.Subcommand()
+			return &command.AliasUserDelCommand{Meta: meta}, nil
+		},
+		"catchall": func() (cli.Command, error) {
+			meta.SubCmdName = c.Subcommand()
+			return &command.CatchAllCommand{Meta: meta}, nil
+		},
+		"catchallset": func() (cli.Command, error) {
+			meta.SubCmdName = c.Subcommand()
+			return &command.CatchAllSetCommand{Meta: meta}, nil
+		},
+		"catchallunset": func() (cli.Command, error) {
+			meta.SubCmdName = c.Subcommand()
+			return &command.CatchAllUnsetCommand{Meta: meta}, nil
+		},
+		"commit": func() (cli.Command, error) {
+			meta.SubCmdName = c.Subcommand()
+			return &command.CommitCommand{Meta: meta}, nil
+		},
+	}
+
+	exitCode, err := c.Run()
+	if err != nil {
+		fmt.Fprintf(meta.UI.ErrorWriter, "%v\n", err)
+	}
+
+	os.Exit(exitCode)
+}
diff --git a/const.go b/const.go
new file mode 100644
index 0000000..2cf9aa6
--- /dev/null
+++ b/const.go
@@ -0,0 +1,23 @@
+package mailfull
+
+// Filenames that are contained in the Repository.
+const (
+	DirNameConfig  = ".mailfull"
+	FileNameConfig = "config"
+
+	FileNameAliasDomains  = ".valiasdomains"
+	FileNameUsersPassword = ".vpasswd"
+	FileNameUserForwards  = ".forward"
+	FileNameAliasUsers    = ".valiases"
+	FileNameCatchAllUser  = ".vcatchall"
+
+	FileNameDbDomains      = "domains"
+	FileNameDbDestinations = "destinations"
+	FileNameDbMaildirs     = "maildirs"
+	FileNameDbLocaltable   = "localtable"
+	FileNameDbForwards     = "forwards"
+	FileNameDbPasswords    = "vpasswd"
+)
+
+// NeverMatchHashedPassword is hash string that is never match with any password.
+const NeverMatchHashedPassword = "{SSHA}!!"
diff --git a/database.go b/database.go
new file mode 100644
index 0000000..6cc5ad8
--- /dev/null
+++ b/database.go
@@ -0,0 +1,245 @@
+package mailfull
+
+import (
+	"fmt"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"sort"
+	"strings"
+)
+
+// GenerateDatabases generates databases from the MailData directory.
+func (r *Repository) GenerateDatabases(md *MailData) error {
+	sort.Sort(DomainSlice(md.Domains))
+	sort.Sort(AliasDomainSlice(md.AliasDomains))
+
+	for _, domain := range md.Domains {
+		sort.Sort(UserSlice(domain.Users))
+		sort.Sort(AliasUserSlice(domain.AliasUsers))
+	}
+
+	// Generate files
+	if err := r.generateDbDomains(md); err != nil {
+		return err
+	}
+	if err := r.generateDbDestinations(md); err != nil {
+		return err
+	}
+	if err := r.generateDbMaildirs(md); err != nil {
+		return err
+	}
+	if err := r.generateDbLocaltable(md); err != nil {
+		return err
+	}
+	if err := r.generateDbForwards(md); err != nil {
+		return err
+	}
+	if err := r.generateDbPasswords(md); err != nil {
+		return err
+	}
+
+	// Generate DBs
+	if err := exec.Command(r.CmdPostmap, filepath.Join(r.DirDatabasePath, FileNameDbDomains)).Run(); err != nil {
+		return err
+	}
+	if err := exec.Command(r.CmdPostmap, filepath.Join(r.DirDatabasePath, FileNameDbDestinations)).Run(); err != nil {
+		return err
+	}
+	if err := exec.Command(r.CmdPostmap, filepath.Join(r.DirDatabasePath, FileNameDbMaildirs)).Run(); err != nil {
+		return err
+	}
+	if err := exec.Command(r.CmdPostmap, filepath.Join(r.DirDatabasePath, FileNameDbLocaltable)).Run(); err != nil {
+		return err
+	}
+	if err := exec.Command(r.CmdPostalias, filepath.Join(r.DirDatabasePath, FileNameDbForwards)).Run(); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (r *Repository) generateDbDomains(md *MailData) error {
+	dbDomains, err := os.Create(filepath.Join(r.DirDatabasePath, FileNameDbDomains))
+	if err != nil {
+		return err
+	}
+	if err := dbDomains.Chown(r.uid, r.gid); err != nil {
+		return err
+	}
+	defer dbDomains.Close()
+
+	for _, domain := range md.Domains {
+		if _, err := fmt.Fprintf(dbDomains, "%s virtual\n", domain.Name()); err != nil {
+			return err
+		}
+	}
+
+	for _, aliasDomain := range md.AliasDomains {
+		if _, err := fmt.Fprintf(dbDomains, "%s virtual\n", aliasDomain.Name()); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (r *Repository) generateDbDestinations(md *MailData) error {
+	dbDestinations, err := os.Create(filepath.Join(r.DirDatabasePath, FileNameDbDestinations))
+	if err != nil {
+		return err
+	}
+	if err := dbDestinations.Chown(r.uid, r.gid); err != nil {
+		return err
+	}
+	defer dbDestinations.Close()
+
+	for _, domain := range md.Domains {
+		// ho-ge.example.com -> ho_ge.example.com
+		underscoredDomainName := domain.Name()
+		underscoredDomainName = strings.Replace(underscoredDomainName, `-`, `_`, -1)
+
+		for _, user := range domain.Users {
+			userName := user.Name()
+			if cu := domain.CatchAllUser; cu != nil && cu.Name() == user.Name() {
+				userName = ""
+			}
+
+			if len(user.Forwards()) > 0 {
+				if _, err := fmt.Fprintf(dbDestinations, "%s@%s %s|%s\n", userName, domain.Name(), underscoredDomainName, user.Name()); err != nil {
+					return err
+				}
+			} else {
+				if _, err := fmt.Fprintf(dbDestinations, "%s@%s %s@%s\n", userName, domain.Name(), user.Name(), domain.Name()); err != nil {
+					return err
+				}
+			}
+
+			for _, aliasDomain := range md.AliasDomains {
+				if aliasDomain.Target() == domain.Name() {
+					if _, err := fmt.Fprintf(dbDestinations, "%s@%s %s@%s\n", userName, aliasDomain.Name(), user.Name(), domain.Name()); err != nil {
+						return err
+					}
+				}
+			}
+		}
+
+		for _, aliasUser := range domain.AliasUsers {
+			if _, err := fmt.Fprintf(dbDestinations, "%s@%s %s\n", aliasUser.Name(), domain.Name(), strings.Join(aliasUser.Targets(), ",")); err != nil {
+				return err
+			}
+
+			for _, aliasDomain := range md.AliasDomains {
+				if aliasDomain.Target() == domain.Name() {
+					if _, err := fmt.Fprintf(dbDestinations, "%s@%s %s@%s\n", aliasUser.Name(), aliasDomain.Name(), aliasUser.Name(), domain.Name()); err != nil {
+						return err
+					}
+				}
+			}
+		}
+	}
+
+	return nil
+}
+
+func (r *Repository) generateDbMaildirs(md *MailData) error {
+	dbMaildirs, err := os.Create(filepath.Join(r.DirDatabasePath, FileNameDbMaildirs))
+	if err != nil {
+		return err
+	}
+	if err := dbMaildirs.Chown(r.uid, r.gid); err != nil {
+		return err
+	}
+	defer dbMaildirs.Close()
+
+	for _, domain := range md.Domains {
+		for _, user := range domain.Users {
+			if _, err := fmt.Fprintf(dbMaildirs, "%s@%s %s/%s/Maildir/\n", user.Name(), domain.Name(), domain.Name(), user.Name()); err != nil {
+				return err
+			}
+		}
+	}
+
+	return nil
+}
+
+func (r *Repository) generateDbLocaltable(md *MailData) error {
+	dbLocaltable, err := os.Create(filepath.Join(r.DirDatabasePath, FileNameDbLocaltable))
+	if err != nil {
+		return err
+	}
+	if err := dbLocaltable.Chown(r.uid, r.gid); err != nil {
+		return err
+	}
+	defer dbLocaltable.Close()
+
+	for _, domain := range md.Domains {
+		// ho-ge.example.com -> ho_ge\.example\.com
+		escapedDomainName := domain.Name()
+		escapedDomainName = strings.Replace(escapedDomainName, `-`, `_`, -1)
+		escapedDomainName = strings.Replace(escapedDomainName, `.`, `\.`, -1)
+
+		if _, err := fmt.Fprintf(dbLocaltable, "/^%s\\|.*$/ local\n", escapedDomainName); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (r *Repository) generateDbForwards(md *MailData) error {
+	dbForwards, err := os.Create(filepath.Join(r.DirDatabasePath, FileNameDbForwards))
+	if err != nil {
+		return err
+	}
+	if err := dbForwards.Chown(r.uid, r.gid); err != nil {
+		return err
+	}
+	defer dbForwards.Close()
+
+	for _, domain := range md.Domains {
+		// ho-ge.example.com -> ho_ge.example.com
+		underscoredDomainName := domain.Name()
+		underscoredDomainName = strings.Replace(underscoredDomainName, `-`, `_`, -1)
+
+		for _, user := range domain.Users {
+			if len(user.Forwards()) > 0 {
+				if _, err := fmt.Fprintf(dbForwards, "%s|%s:%s\n", underscoredDomainName, user.Name(), strings.Join(user.Forwards(), ",")); err != nil {
+					return err
+				}
+			} else {
+				if _, err := fmt.Fprintf(dbForwards, "%s|%s:/dev/null\n", underscoredDomainName, user.Name()); err != nil {
+					return err
+				}
+			}
+		}
+	}
+
+	// drop real user
+	if _, err := fmt.Fprintf(dbForwards, "%s:/dev/null\n", r.Username); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (r *Repository) generateDbPasswords(md *MailData) error {
+	dbPasswords, err := os.Create(filepath.Join(r.DirDatabasePath, FileNameDbPasswords))
+	if err != nil {
+		return err
+	}
+	if err := dbPasswords.Chown(r.uid, r.gid); err != nil {
+		return err
+	}
+	defer dbPasswords.Close()
+
+	for _, domain := range md.Domains {
+		for _, user := range domain.Users {
+			if _, err := fmt.Fprintf(dbPasswords, "%s@%s:%s\n", user.Name(), domain.Name(), user.HashedPassword()); err != nil {
+				return err
+			}
+		}
+	}
+
+	return nil
+}
diff --git a/domain.go b/domain.go
new file mode 100644
index 0000000..af499e0
--- /dev/null
+++ b/domain.go
@@ -0,0 +1,184 @@
+package mailfull
+
+import (
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"syscall"
+	"time"
+)
+
+// Domain represents a Domain.
+type Domain struct {
+	name         string
+	Users        []*User
+	AliasUsers   []*AliasUser
+	CatchAllUser *CatchAllUser
+}
+
+// DomainSlice attaches the methods of sort.Interface to []*Domain.
+type DomainSlice []*Domain
+
+func (p DomainSlice) Len() int           { return len(p) }
+func (p DomainSlice) Less(i, j int) bool { return p[i].Name() < p[j].Name() }
+func (p DomainSlice) Swap(i, j int)      { p[i], p[j] = p[j], p[i] }
+
+// NewDomain creates a new Domain instance.
+func NewDomain(name string) (*Domain, error) {
+	if !validDomainName(name) {
+		return nil, ErrInvalidDomainName
+	}
+
+	d := &Domain{
+		name: name,
+	}
+
+	return d, nil
+}
+
+// Name returns name.
+func (d *Domain) Name() string {
+	return d.name
+}
+
+// Domains returns a Domain slice.
+func (r *Repository) Domains() ([]*Domain, error) {
+	fileInfos, err := ioutil.ReadDir(r.DirMailDataPath)
+	if err != nil {
+		return nil, err
+	}
+
+	domains := make([]*Domain, 0, len(fileInfos))
+
+	for _, fileInfo := range fileInfos {
+		if !fileInfo.IsDir() {
+			continue
+		}
+
+		name := fileInfo.Name()
+
+		domain, err := NewDomain(name)
+		if err != nil {
+			continue
+		}
+
+		domains = append(domains, domain)
+	}
+
+	return domains, nil
+}
+
+// Domain returns a Domain of the input name.
+func (r *Repository) Domain(domainName string) (*Domain, error) {
+	if !validDomainName(domainName) {
+		return nil, ErrInvalidDomainName
+	}
+
+	fileInfo, err := os.Stat(filepath.Join(r.DirMailDataPath, domainName))
+	if err != nil {
+		if err.(*os.PathError).Err == syscall.ENOENT {
+			return nil, nil
+		}
+
+		return nil, err
+	}
+
+	if !fileInfo.IsDir() {
+		return nil, nil
+	}
+
+	name := domainName
+
+	domain, err := NewDomain(name)
+	if err != nil {
+		return nil, err
+	}
+
+	return domain, nil
+}
+
+// DomainCreate creates the input Domain.
+func (r *Repository) DomainCreate(domain *Domain) error {
+	existDomain, err := r.Domain(domain.Name())
+	if err != nil {
+		return err
+	}
+	if existDomain != nil {
+		return ErrDomainAlreadyExist
+	}
+	existAliasDomain, err := r.AliasDomain(domain.Name())
+	if err != nil {
+		return err
+	}
+	if existAliasDomain != nil {
+		return ErrAliasDomainAlreadyExist
+	}
+
+	domainDirPath := filepath.Join(r.DirMailDataPath, domain.Name())
+
+	if err := os.Mkdir(domainDirPath, 0700); err != nil {
+		return err
+	}
+	if err := os.Chown(domainDirPath, r.uid, r.gid); err != nil {
+		return err
+	}
+
+	usersPasswordFile, err := os.OpenFile(filepath.Join(domainDirPath, FileNameUsersPassword), os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0600)
+	if err != nil {
+		return err
+	}
+	if err := usersPasswordFile.Chown(r.uid, r.gid); err != nil {
+		return err
+	}
+	usersPasswordFile.Close()
+
+	aliasUsersFile, err := os.OpenFile(filepath.Join(domainDirPath, FileNameAliasUsers), os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0600)
+	if err != nil {
+		return err
+	}
+	if err := aliasUsersFile.Chown(r.uid, r.gid); err != nil {
+		return err
+	}
+	aliasUsersFile.Close()
+
+	catchAllUserFile, err := os.OpenFile(filepath.Join(domainDirPath, FileNameCatchAllUser), os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0600)
+	if err != nil {
+		return err
+	}
+	if err := catchAllUserFile.Chown(r.uid, r.gid); err != nil {
+		return err
+	}
+	catchAllUserFile.Close()
+
+	return nil
+}
+
+// DomainRemove removes a Domain of the input name.
+func (r *Repository) DomainRemove(domainName string) error {
+	existDomain, err := r.Domain(domainName)
+	if err != nil {
+		return err
+	}
+	if existDomain == nil {
+		return ErrDomainNotExist
+	}
+
+	aliasDomains, err := r.AliasDomains()
+	if err != nil {
+		return err
+	}
+	for _, aliasDomain := range aliasDomains {
+		if aliasDomain.Target() == domainName {
+			return ErrDomainIsAliasDomainTarget
+		}
+	}
+
+	domainDirPath := filepath.Join(r.DirMailDataPath, domainName)
+	domainBackupDirPath := filepath.Join(r.DirMailDataPath, "."+domainName+".deleted."+time.Now().Format("20060102150405"))
+
+	if err := os.Rename(domainDirPath, domainBackupDirPath); err != nil {
+		return err
+	}
+
+	return nil
+}
diff --git a/generateconfig.go b/generateconfig.go
new file mode 100644
index 0000000..a2cc75f
--- /dev/null
+++ b/generateconfig.go
@@ -0,0 +1,140 @@
+package mailfull
+
+import (
+	"fmt"
+	"path/filepath"
+	"time"
+)
+
+// GenerateConfigPostfix generate a configuration for Postfix.
+func (r *Repository) GenerateConfigPostfix() string {
+	cfg := fmt.Sprintf(`
+#
+# Sample configuration: main.cf
+# Generated by mailfull %s on %s
+#
+
+#myhostname = host.example.com
+mydomain = $myhostname
+myorigin = $mydomain
+
+inet_interfaces = all
+mydestination = $myhostname, localhost.$mydomain, localhost, $mydomain
+mynetworks_style = host
+recipient_delimiter = -
+message_size_limit = 10240000
+mailbox_size_limit = 51200000
+virtual_mailbox_limit = 51200000
+
+virtual_mailbox_domains = hash:%s
+virtual_mailbox_base = %s
+virtual_mailbox_maps = hash:%s
+virtual_uid_maps = static:%d
+virtual_gid_maps = static:%d
+virtual_alias_maps = hash:%s
+transport_maps = regexp:%s
+alias_maps = hash:/etc/aliases, hash:%s
+alias_database = hash:/etc/aliases, hash:%s
+
+smtpd_sasl_auth_enable = yes
+smtpd_sasl_local_domain = $myhostname
+smtpd_recipient_restrictions = permit_mynetworks, permit_sasl_authenticated, reject_unauth_destination
+smtpd_sasl_type = dovecot
+smtpd_sasl_path = private/auth
+
+smtpd_tls_cert_file = /etc/pki/dovecot/certs/dovecot.pem
+smtpd_tls_key_file = /etc/pki/dovecot/private/dovecot.pem
+#smtpd_tls_CAfile =
+smtpd_tls_session_cache_database = btree:/etc/postfix/smtpd_scache
+smtpd_tls_mandatory_protocols = !SSLv2, !SSLv3
+
+smtp_tls_security_level = may
+smtp_tls_loglevel = 1
+smtpd_tls_security_level = may
+smtpd_tls_loglevel = 1
+`,
+		Version, time.Now().Format(time.RFC3339),
+		filepath.Join(r.DirDatabasePath, FileNameDbDomains),
+		r.DirMailDataPath,
+		filepath.Join(r.DirDatabasePath, FileNameDbMaildirs),
+		r.uid,
+		r.gid,
+		filepath.Join(r.DirDatabasePath, FileNameDbDestinations),
+		filepath.Join(r.DirDatabasePath, FileNameDbLocaltable),
+		filepath.Join(r.DirDatabasePath, FileNameDbForwards),
+		filepath.Join(r.DirDatabasePath, FileNameDbForwards),
+	)
+
+	return cfg[1:]
+}
+
+// GenerateConfigDovecot generate a configuration for Dovecot.
+func (r *Repository) GenerateConfigDovecot() string {
+	cfg := fmt.Sprintf(`
+#
+# Sample configuration: dovecot.conf
+# Generated by mailfull %s on %s
+#
+
+protocols = imap pop3
+auth_mechanisms = plain login
+mail_location = maildir:~/Maildir
+
+ssl = yes
+ssl_cert = </etc/pki/dovecot/certs/dovecot.pem
+ssl_key = </etc/pki/dovecot/private/dovecot.pem
+#ssl_ca =
+
+disable_plaintext_auth = yes
+
+service imap-login {
+  inet_listener imap {
+    port = 143
+  }
+  inet_listener imaps {
+    port = 993
+    ssl = yes
+  }
+}
+
+service pop3-login {
+  inet_listener pop3 {
+    port = 110
+  }
+  inet_listener pop3s {
+    port = 995
+    ssl = yes
+  }
+}
+
+service auth {
+  unix_listener /var/spool/postfix/private/auth {
+    mode = 0666
+    user = postfix
+    group = postfix
+  }
+}
+
+passdb {
+  driver = passwd-file
+  args = %s
+}
+userdb {
+  driver = static
+  args = uid=%d gid=%d home=%s/%%d/%%n
+}
+
+passdb {
+  driver = pam
+}
+userdb {
+  driver = passwd
+}
+`,
+		Version, time.Now().Format(time.RFC3339),
+		filepath.Join(r.DirDatabasePath, FileNameDbPasswords),
+		r.uid, r.gid, r.DirMailDataPath,
+	)
+
+	return cfg[1:]
+}
diff --git a/maildata.go b/maildata.go
new file mode 100644
index 0000000..7e32b38
--- /dev/null
+++ b/maildata.go
@@ -0,0 +1,47 @@
+package mailfull
+
+// MailData represents a MailData.
+type MailData struct {
+	Domains      []*Domain
+	AliasDomains []*AliasDomain
+}
+
+// MailData returns a MailData.
+func (r *Repository) MailData() (*MailData, error) {
+	domains, err := r.Domains()
+	if err != nil {
+		return nil, err
+	}
+
+	aliasDomains, err := r.AliasDomains()
+	if err != nil {
+		return nil, err
+	}
+
+	for _, domain := range domains {
+		users, err := r.Users(domain.Name())
+		if err != nil {
+			return nil, err
+		}
+		domain.Users = users
+
+		aliasUsers, err := r.AliasUsers(domain.Name())
+		if err != nil {
+			return nil, err
+		}
+		domain.AliasUsers = aliasUsers
+
+		catchAllUser, err := r.CatchAllUser(domain.Name())
+		if err != nil {
+			return nil, err
+		}
+		domain.CatchAllUser = catchAllUser
+	}
+
+	mailData := &MailData{
+		Domains:      domains,
+		AliasDomains: aliasDomains,
+	}
+
+	return mailData, nil
+}
diff --git a/mailfull.go b/mailfull.go
new file mode 100644
index 0000000..86cb38a
--- /dev/null
+++ b/mailfull.go
@@ -0,0 +1,4 @@
+/*
+Package mailfull contains operations for a mailfull repository.
+*/
+package mailfull
diff --git a/repository.go b/repository.go
new file mode 100644
index 0000000..7372956
--- /dev/null
+++ b/repository.go
@@ -0,0 +1,290 @@
+package mailfull
+
+import (
+	"errors"
+	"os"
+	"os/user"
+	"path/filepath"
+	"strconv"
+	"syscall"
+
+	"github.com/BurntSushi/toml"
+)
+
+// Errors for the Repository.
+var (
+	ErrInvalidRepository = errors.New("invalid repository")
+	ErrNotRepository     = errors.New("not a Mailfull repository (or any of the parent directories)")
+	ErrRepositoryExist   = errors.New("a Mailfull repository exists")
+)
+
+// Errors for the operation of the Repository.
+var (
+	ErrDomainNotExist            = errors.New("Domain: not exist")
+	ErrDomainAlreadyExist        = errors.New("Domain: already exist")
+	ErrDomainIsAliasDomainTarget = errors.New("Domain: is set as alias")
+
+	ErrAliasDomainNotExist     = errors.New("AliasDomain: not exist")
+	ErrAliasDomainAlreadyExist = errors.New("AliasDomain: already exist")
+
+	ErrUserNotExist       = errors.New("User: not exist")
+	ErrUserAlreadyExist   = errors.New("User: already exist")
+	ErrUserIsCatchAllUser = errors.New("User: is set as catchall")
+
+	ErrAliasUserNotExist     = errors.New("AliasUser: not exist")
+	ErrAliasUserAlreadyExist = errors.New("AliasUser: already exist")
+
+	ErrInvalidFormatUsersPassword = errors.New("User: password file invalid format")
+	ErrInvalidFormatAliasDomain   = errors.New("AliasDomain: file invalid format")
+	ErrInvalidFormatAliasUsers    = errors.New("AliasUsers: file invalid format")
+)
+
+// RepositoryConfig is used to configure a Repository.
+type RepositoryConfig struct {
+	DirDatabasePath string `toml:"dir_database"`
+	DirMailDataPath string `toml:"dir_maildata"`
+	Username        string `toml:"username"`
+	CmdPostalias    string `toml:"postalias"`
+	CmdPostmap      string `toml:"postmap"`
+}
+
+// Normalize normalizes paramaters of the RepositoryConfig.
+func (c *RepositoryConfig) Normalize(rootPath string) {
+	if !filepath.IsAbs(c.DirDatabasePath) {
+		c.DirDatabasePath = filepath.Join(rootPath, c.DirDatabasePath)
+	}
+	if !filepath.IsAbs(c.DirMailDataPath) {
+		c.DirMailDataPath = filepath.Join(rootPath, c.DirMailDataPath)
+	}
+
+	if filepath.Base(c.CmdPostalias) != c.CmdPostalias {
+		if !filepath.IsAbs(c.CmdPostalias) {
+			c.CmdPostalias = filepath.Join(rootPath, c.CmdPostalias)
+		}
+	}
+
+	if filepath.Base(c.CmdPostmap) != c.CmdPostmap {
+		if !filepath.IsAbs(c.CmdPostmap) {
+			c.CmdPostmap = filepath.Join(rootPath, c.CmdPostmap)
+		}
+	}
+}
+
+// DefaultRepositoryConfig returns a RepositoryConfig with default parameter.
+func DefaultRepositoryConfig() *RepositoryConfig {
+	c := &RepositoryConfig{
+		DirDatabasePath: "./etc",
+		DirMailDataPath: "./domains",
+		Username:        "",
+		CmdPostalias:    "postalias",
+		CmdPostmap:      "postmap",
+	}
+
+	return c
+}
+
+// Repository represents a Repository.
+type Repository struct {
+	*RepositoryConfig
+
+	uid int
+	gid int
+}
+
+// NewRepository creates a new Repository instance.
+func NewRepository(c *RepositoryConfig) (*Repository, error) {
+	u, err := user.Lookup(c.Username)
+	if err != nil {
+		return nil, err
+	}
+	uid, err := strconv.Atoi(u.Uid)
+	if err != nil {
+		return nil, err
+	}
+	gid, err := strconv.Atoi(u.Gid)
+	if err != nil {
+		return nil, err
+	}
+
+	r := &Repository{
+		RepositoryConfig: c,
+
+		uid: uid,
+		gid: gid,
+	}
+
+	return r, nil
+}
+
+// OpenRepository opens a Repository and creates a new Repository instance.
+func OpenRepository(basePath string) (*Repository, error) {
+	rootPath, err := filepath.Abs(basePath)
+	if err != nil {
+		return nil, err
+	}
+
+	for {
+		configDirPath := filepath.Join(rootPath, DirNameConfig)
+
+		fi, errStat := os.Stat(configDirPath)
+		if errStat != nil {
+			if errStat.(*os.PathError).Err != syscall.ENOENT {
+				return nil, errStat
+			}
+		} else {
+			if fi.IsDir() {
+				break
+			} else {
+				return nil, ErrInvalidRepository
+			}
+		}
+
+		parentPath := filepath.Clean(filepath.Join(rootPath, ".."))
+		if rootPath == parentPath {
+			return nil, ErrNotRepository
+		}
+		rootPath = parentPath
+	}
+
+	configFilePath := filepath.Join(rootPath, DirNameConfig, FileNameConfig)
+
+	fi, err := os.Stat(configFilePath)
+	if err != nil {
+		return nil, err
+	}
+	if fi.IsDir() {
+		return nil, ErrInvalidRepository
+	}
+
+	configFile, err := os.Open(configFilePath)
+	if err != nil {
+		return nil, err
+	}
+	defer configFile.Close()
+
+	c := DefaultRepositoryConfig()
+	if _, err = toml.DecodeReader(configFile, c); err != nil {
+		return nil, err
+	}
+
+	c.Normalize(rootPath)
+
+	r, err := NewRepository(c)
+	if err != nil {
+		return nil, err
+	}
+
+	return r, nil
+}
+
+// InitRepository initializes the input directory as a Repository.
+func InitRepository(rootPath string) error {
+	rootPath, err := filepath.Abs(rootPath)
+	if err != nil {
+		return err
+	}
+
+	configDirPath := filepath.Join(rootPath, DirNameConfig)
+
+	fi, err := os.Stat(configDirPath)
+	if err != nil {
+		if err.(*os.PathError).Err == syscall.ENOENT {
+			if err = os.Mkdir(configDirPath, 0777); err != nil {
+				return err
+			}
+		} else {
+			return err
+		}
+	} else {
+		if !fi.IsDir() {
+			return ErrInvalidRepository
+		}
+	}
+
+	configFilePath := filepath.Join(configDirPath, FileNameConfig)
+
+	fi, err = os.Stat(configFilePath)
+	if err != nil {
+		if err.(*os.PathError).Err != syscall.ENOENT {
+			return err
+		}
+	} else {
+		if fi.IsDir() {
+			return ErrInvalidRepository
+		}
+
+		return ErrRepositoryExist
+	}
+
+	configFile, err := os.Create(configFilePath)
+	if err != nil {
+		return nil
+	}
+	defer configFile.Close()
+
+	u, err := user.Current()
+	if err != nil {
+		return nil
+	}
+
+	c := DefaultRepositoryConfig()
+	c.Username = u.Username
+
+	enc := toml.NewEncoder(configFile)
+	if err := enc.Encode(c); err != nil {
+		return err
+	}
+
+	c.Normalize(rootPath)
+
+	fi, err = os.Stat(c.DirDatabasePath)
+	if err != nil {
+		if err.(*os.PathError).Err == syscall.ENOENT {
+			if err = os.Mkdir(c.DirDatabasePath, 0777); err != nil {
+				return err
+			}
+		} else {
+			return err
+		}
+	} else {
+		if !fi.IsDir() {
+			return ErrInvalidRepository
+		}
+	}
+
+	fi, err = os.Stat(c.DirMailDataPath)
+	if err != nil {
+		if err.(*os.PathError).Err == syscall.ENOENT {
+			if err = os.Mkdir(c.DirMailDataPath, 0700); err != nil {
+				return err
+			}
+		} else {
+			return err
+		}
+	} else {
+		if !fi.IsDir() {
+			return ErrInvalidRepository
+		}
+	}
+
+	aliasDomainsFileName := filepath.Join(c.DirMailDataPath, FileNameAliasDomains)
+
+	fi, err = os.Stat(aliasDomainsFileName)
+	if err != nil {
+		if err.(*os.PathError).Err != syscall.ENOENT {
+			return err
+		}
+	} else {
+		if fi.IsDir() {
+			return ErrInvalidRepository
+		}
+	}
+
+	aliasDomainsFile, err := os.OpenFile(aliasDomainsFileName, os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0600)
+	if err != nil {
+		return nil
+	}
+	defer aliasDomainsFile.Close()
+
+	return nil
+}
diff --git a/user.go b/user.go
new file mode 100644
index 0000000..cdf3bec
--- /dev/null
+++ b/user.go
@@ -0,0 +1,405 @@
+package mailfull
+
+import (
+	"bufio"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"sort"
+	"strings"
+	"syscall"
+	"time"
+)
+
+// User represents a User.
+type User struct {
+	name           string
+	hashedPassword string
+	forwards       []string
+}
+
+// UserSlice attaches the methods of sort.Interface to []*User.
+type UserSlice []*User
+
+func (p UserSlice) Len() int           { return len(p) }
+func (p UserSlice) Less(i, j int) bool { return p[i].Name() < p[j].Name() }
+func (p UserSlice) Swap(i, j int)      { p[i], p[j] = p[j], p[i] }
+
+// NewUser creates a new User instance.
+func NewUser(name, hashedPassword string, forwards []string) (*User, error) {
+	u := &User{}
+
+	if err := u.setName(name); err != nil {
+		return nil, err
+	}
+
+	u.SetHashedPassword(hashedPassword)
+	u.SetForwards(forwards)
+
+	return u, nil
+}
+
+// setName sets the name.
+func (u *User) setName(name string) error {
+	if !validUserName(name) {
+		return ErrInvalidUserName
+	}
+
+	u.name = name
+
+	return nil
+}
+
+// Name returns name.
+func (u *User) Name() string {
+	return u.name
+}
+
+// SetHashedPassword sets the hashed password.
+func (u *User) SetHashedPassword(hashedPassword string) {
+	u.hashedPassword = hashedPassword
+}
+
+// HashedPassword returns hashedPassword.
+func (u *User) HashedPassword() string {
+	return u.hashedPassword
+}
+
+// SetForwards sets forwards.
+func (u *User) SetForwards(forwards []string) {
+	u.forwards = forwards
+}
+
+// Forwards returns forwards.
+func (u *User) Forwards() []string {
+	return u.forwards
+}
+
+// Users returns a User slice.
+func (r *Repository) Users(domainName string) ([]*User, error) {
+	domain, err := r.Domain(domainName)
+	if err != nil {
+		return nil, err
+	}
+	if domain == nil {
+		return nil, ErrDomainNotExist
+	}
+
+	hashedPasswords, err := r.usersHashedPassword(domainName)
+	if err != nil {
+		return nil, err
+	}
+
+	fileInfos, err := ioutil.ReadDir(filepath.Join(r.DirMailDataPath, domainName))
+	if err != nil {
+		return nil, err
+	}
+
+	users := make([]*User, 0, len(fileInfos))
+
+	for _, fileInfo := range fileInfos {
+		if !fileInfo.IsDir() {
+			continue
+		}
+
+		name := fileInfo.Name()
+
+		forwards, err := r.userForwards(domainName, name)
+		if err != nil {
+			return nil, err
+		}
+
+		hashedPassword, ok := hashedPasswords[name]
+		if !ok {
+			hashedPassword = ""
+		}
+
+		user, err := NewUser(name, hashedPassword, forwards)
+		if err != nil {
+			continue
+		}
+
+		users = append(users, user)
+	}
+
+	return users, nil
+}
+
+// User returns a User of the input name.
+func (r *Repository) User(domainName, userName string) (*User, error) {
+	domain, err := r.Domain(domainName)
+	if err != nil {
+		return nil, err
+	}
+	if domain == nil {
+		return nil, ErrDomainNotExist
+	}
+
+	if !validUserName(userName) {
+		return nil, ErrInvalidUserName
+	}
+
+	hashedPasswords, err := r.usersHashedPassword(domainName)
+	if err != nil {
+		return nil, err
+	}
+
+	fileInfo, err := os.Stat(filepath.Join(r.DirMailDataPath, domainName, userName))
+	if err != nil {
+		if err.(*os.PathError).Err == syscall.ENOENT {
+			return nil, nil
+		}
+
+		return nil, err
+	}
+
+	if !fileInfo.IsDir() {
+		return nil, nil
+	}
+
+	name := userName
+
+	forwards, err := r.userForwards(domainName, name)
+	if err != nil {
+		return nil, err
+	}
+
+	hashedPassword, ok := hashedPasswords[name]
+	if !ok {
+		hashedPassword = ""
+	}
+
+	user, err := NewUser(name, hashedPassword, forwards)
+	if err != nil {
+		return nil, err
+	}
+
+	return user, nil
+}
+
+// usersHashedPassword returns a string map of usernames to the hashed password.
+func (r *Repository) usersHashedPassword(domainName string) (map[string]string, error) {
+	if !validDomainName(domainName) {
+		return nil, ErrInvalidDomainName
+	}
+
+	file, err := os.Open(filepath.Join(r.DirMailDataPath, domainName, FileNameUsersPassword))
+	if err != nil {
+		return nil, err
+	}
+	defer file.Close()
+
+	hashedPasswords := map[string]string{}
+
+	scanner := bufio.NewScanner(file)
+	for scanner.Scan() {
+		words := strings.Split(scanner.Text(), ":")
+		if len(words) != 2 {
+			return nil, ErrInvalidFormatUsersPassword
+		}
+
+		name := words[0]
+		hashedPassword := words[1]
+
+		hashedPasswords[name] = hashedPassword
+	}
+
+	if err := scanner.Err(); err != nil {
+		return nil, err
+	}
+
+	return hashedPasswords, nil
+}
+
+// userForwards returns a string slice of forwards that the input name has.
+func (r *Repository) userForwards(domainName, userName string) ([]string, error) {
+	if !validDomainName(domainName) {
+		return nil, ErrInvalidDomainName
+	}
+	if !validUserName(userName) {
+		return nil, ErrInvalidUserName
+	}
+
+	file, err := os.Open(filepath.Join(r.DirMailDataPath, domainName, userName, FileNameUserForwards))
+	if err != nil {
+		if err.(*os.PathError).Err == syscall.ENOENT {
+			return nil, nil
+		}
+
+		return nil, err
+	}
+	defer file.Close()
+
+	forwards := make([]string, 0, 5)
+
+	scanner := bufio.NewScanner(file)
+	for scanner.Scan() {
+		forwards = append(forwards, scanner.Text())
+	}
+
+	if err := scanner.Err(); err != nil {
+		return nil, err
+	}
+
+	return forwards, nil
+}
+
+// UserCreate creates the input User.
+func (r *Repository) UserCreate(domainName string, user *User) error {
+	existUser, err := r.User(domainName, user.Name())
+	if err != nil {
+		return err
+	}
+	if existUser != nil {
+		return ErrUserAlreadyExist
+	}
+	existAliasUser, err := r.AliasUser(domainName, user.Name())
+	if err != nil {
+		return err
+	}
+	if existAliasUser != nil {
+		return ErrAliasUserAlreadyExist
+	}
+
+	userDirPath := filepath.Join(r.DirMailDataPath, domainName, user.Name())
+
+	dirNames := []string{
+		userDirPath,
+		filepath.Join(userDirPath, "Maildir"),
+		filepath.Join(userDirPath, "Maildir/cur"),
+		filepath.Join(userDirPath, "Maildir/new"),
+		filepath.Join(userDirPath, "Maildir/tmp"),
+	}
+	for _, dirName := range dirNames {
+		if err := os.Mkdir(dirName, 0700); err != nil {
+			return err
+		}
+		if err := os.Chown(dirName, r.uid, r.gid); err != nil {
+			return err
+		}
+	}
+
+	if err := r.UserUpdate(domainName, user); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// UserUpdate updates the input User.
+func (r *Repository) UserUpdate(domainName string, user *User) error {
+	existUser, err := r.User(domainName, user.Name())
+	if err != nil {
+		return err
+	}
+	if existUser == nil {
+		return ErrUserNotExist
+	}
+
+	hashedPasswords, err := r.usersHashedPassword(domainName)
+	if err != nil {
+		return err
+	}
+	hashedPasswords[user.Name()] = user.HashedPassword()
+	if err := r.writeUsersPasswordFile(domainName, hashedPasswords); err != nil {
+		return err
+	}
+
+	if err := r.writeUserForwardsFile(domainName, user.Name(), user.Forwards()); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// UserRemove removes a User of the input name.
+func (r *Repository) UserRemove(domainName, userName string) error {
+	existUser, err := r.User(domainName, userName)
+	if err != nil {
+		return err
+	}
+	if existUser == nil {
+		return ErrUserNotExist
+	}
+
+	catchAllUser, err := r.CatchAllUser(domainName)
+	if err != nil {
+		return err
+	}
+	if catchAllUser != nil && catchAllUser.Name() == userName {
+		return ErrUserIsCatchAllUser
+	}
+
+	hashedPasswords, err := r.usersHashedPassword(domainName)
+	if err != nil {
+		return err
+	}
+	delete(hashedPasswords, userName)
+	if err := r.writeUsersPasswordFile(domainName, hashedPasswords); err != nil {
+		return err
+	}
+
+	userDirPath := filepath.Join(r.DirMailDataPath, domainName, userName)
+	userBackupDirPath := filepath.Join(r.DirMailDataPath, domainName, "."+userName+".deleted."+time.Now().Format("20060102150405"))
+
+	if err := os.Rename(userDirPath, userBackupDirPath); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// writeUsersPasswordFile writes passwords of each users to the file.
+func (r *Repository) writeUsersPasswordFile(domainName string, hashedPasswords map[string]string) error {
+	if !validDomainName(domainName) {
+		return ErrInvalidDomainName
+	}
+
+	keys := make([]string, 0, len(hashedPasswords))
+	for key := range hashedPasswords {
+		keys = append(keys, key)
+	}
+	sort.Strings(keys)
+
+	file, err := os.OpenFile(filepath.Join(r.DirMailDataPath, domainName, FileNameUsersPassword), os.O_RDWR|os.O_TRUNC, 0600)
+	if err != nil {
+		return err
+	}
+	defer file.Close()
+
+	for _, key := range keys {
+		if _, err := fmt.Fprintf(file, "%s:%s\n", key, hashedPasswords[key]); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+// writeUserForwardsFile writes forwards to user's forward file.
+func (r *Repository) writeUserForwardsFile(domainName, userName string, forwards []string) error {
+	if !validDomainName(domainName) {
+		return ErrInvalidDomainName
+	}
+	if !validUserName(userName) {
+		return ErrInvalidUserName
+	}
+
+	file, err := os.OpenFile(filepath.Join(r.DirMailDataPath, domainName, userName, FileNameUserForwards), os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0600)
+	if err != nil {
+		return err
+	}
+	if err := file.Chown(r.uid, r.gid); err != nil {
+		return err
+	}
+	defer file.Close()
+
+	for _, forward := range forwards {
+		if _, err := fmt.Fprintf(file, "%s\n", forward); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
diff --git a/valid.go b/valid.go
new file mode 100644
index 0000000..8061cd3
--- /dev/null
+++ b/valid.go
@@ -0,0 +1,52 @@
+package mailfull
+
+import (
+	"errors"
+	"regexp"
+)
+
+// Errors for incorrect format.
+var (
+	ErrInvalidDomainName        = errors.New("Domain: name incorrect format")
+	ErrInvalidAliasDomainName   = errors.New("AliasDomain: name incorrect format")
+	ErrInvalidAliasDomainTarget = errors.New("AliasDomain: target incorrect format")
+	ErrInvalidUserName          = errors.New("User: name incorrect format")
+	ErrInvalidAliasUserName     = errors.New("AliasUser: name incorrect format")
+	ErrInvalidAliasUserTarget   = errors.New("AliasUser: target incorrect format")
+	ErrInvalidCatchAllUserName  = errors.New("CatchAllUser: name incorrect format")
+)
+
+// validDomainName returns true if the input is correct format.
+func validDomainName(name string) bool {
+	return regexp.MustCompile(`^([A-Za-z0-9\-]+\.)*[A-Za-z]+$`).MatchString(name)
+}
+
+// validAliasDomainName returns true if the input is correct format.
+func validAliasDomainName(name string) bool {
+	return regexp.MustCompile(`^([A-Za-z0-9\-]+\.)*[A-Za-z]+$`).MatchString(name)
+}
+
+// validAliasDomainTarget returns true if the input is correct format.
+func validAliasDomainTarget(target string) bool {
+	return regexp.MustCompile(`^([A-Za-z0-9\-]+\.)*[A-Za-z]+$`).MatchString(target)
+}
+
+// validUserName returns true if the input is correct format.
+func validUserName(name string) bool {
+	return regexp.MustCompile(`^[^\s@]+$`).MatchString(name)
+}
+
+// validAliasUserName returns true if the input is correct format.
+func validAliasUserName(name string) bool {
+	return regexp.MustCompile(`^[^\s@]+$`).MatchString(name)
+}
+
+// validAliasUserTarget returns true if the input is correct format.
+func validAliasUserTarget(target string) bool {
+	return regexp.MustCompile(`^[^\s@]+@([A-Za-z0-9\-]+\.)*[A-Za-z]+$`).MatchString(target)
+}
+
+// validCatchAllUserName returns true if the input is correct format.
+func validCatchAllUserName(name string) bool {
+	return regexp.MustCompile(`^[^\s@]+$`).MatchString(name)
+}
diff --git a/version.go b/version.go
new file mode 100644
index 0000000..2d2cf0d
--- /dev/null
+++ b/version.go
@@ -0,0 +1,4 @@
+package mailfull
+
+// Version is a version number.
+const Version = "0.0.1"