diff --git a/.gitignore b/.gitignore
index 39a7681..28875c2 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,6 @@
-/cli/mailfull/mailfull
+/vendor
+/build
+/release
+/github_token
+
+/cmd/mailfull/mailfull
diff --git a/Gomfile b/Gomfile
new file mode 100644
index 0000000..c7ebd62
--- /dev/null
+++ b/Gomfile
@@ -0,0 +1,6 @@
+gom 'github.com/BurntSushi/toml'
+gom 'github.com/armon/go-radix'
+gom 'github.com/bgentry/speakeasy'
+gom 'github.com/jsimonetti/pwscheme'
+gom 'github.com/mattn/go-isatty'
+gom 'github.com/mitchellh/cli'
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..f3e73c9
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,53 @@
+GOVERSION=$(shell go version)
+GOOS=$(word 1,$(subst /, ,$(lastword $(GOVERSION))))
+GOARCH=$(word 2,$(subst /, ,$(lastword $(GOVERSION))))
+DIR_BUILD=build
+DIR_RELEASE=release
+VERSION=$(patsubst "%",%,$(lastword $(shell grep 'const Version' version.go)))
+
+.PHONY: build build-linux-amd64 build-linux-386 clean
+
+default: build
+
+installdeps:
+	gom install
+
+build:
+	go build -ldflags "-X main.gittag=`git rev-parse --short HEAD`" -v -o build/mailfull_$(GOOS)_$(GOARCH)/mailfull cmd/mailfull/main.go
+
+build-linux-amd64:
+	docker run --rm -v $(PWD):/go/src/github.com/directorz/mailfull-go -w /go/src/github.com/directorz/mailfull-go \
+	-e GOOS=linux -e GOARCH=amd64 golang:1.7 \
+	go build -ldflags "-X main.gittag=`git rev-parse --short HEAD`" -v -o "build/mailfull_linux_amd64/mailfull" cmd/mailfull/main.go
+
+build-linux-386:
+	docker run --rm -v $(PWD):/go/src/github.com/directorz/mailfull-go -w /go/src/github.com/directorz/mailfull-go \
+	-e GOOS=linux -e GOARCH=386 golang:1.7 \
+	go build -ldflags "-X main.gittag=`git rev-parse --short HEAD`" -v -o "build/mailfull_linux_386/mailfull" cmd/mailfull/main.go
+
+release: release-linux-amd64 release-linux-386
+
+release-linux-amd64: build-linux-amd64
+	@$(MAKE) release-doc release-targz GOOS=linux GOARCH=amd64
+
+release-linux-386: build-linux-386
+	@$(MAKE) release-doc release-targz GOOS=linux GOARCH=386
+
+release-doc:
+	cp -a README.md doc $(DIR_BUILD)/mailfull_$(GOOS)_$(GOARCH)
+
+release-targz: dir-$(DIR_RELEASE)
+	tar zcfp $(DIR_RELEASE)/mailfull_$(GOOS)_$(GOARCH).tar.gz -C $(DIR_BUILD) mailfull_$(GOOS)_$(GOARCH)
+
+dir-$(DIR_RELEASE):
+	mkdir -p $(DIR_RELEASE)
+
+release-upload: release-linux-amd64 release-linux-386 release-github-token
+	ghr -u directorz -r mailfull-go -t $(shell cat github_token) --replace --draft $(VERSION) $(DIR_RELEASE)
+
+release-github-token: github_token
+	@echo "file \"github_token\" is required"
+
+clean:
+	-rm -rf $(DIR_BUILD)
+	-rm -rf $(DIR_RELEASE)
diff --git a/README.md b/README.md
index 55d0832..9ead86e 100644
--- a/README.md
+++ b/README.md
@@ -39,6 +39,7 @@ Initialize a directory as a Mailfull repository.
 ```
 $ mkdir /path/to/repo && cd /path/to/repo
 $ mailfull init
+$ mailfull commit
 ```
 
 Generate configurations for Postfix and Dovecot. (Edit as needed.)
diff --git a/cmd/mailfull/command/usercheckpw.go b/cmd/mailfull/command/usercheckpw.go
index 6fd8e37..66d93af 100644
--- a/cmd/mailfull/command/usercheckpw.go
+++ b/cmd/mailfull/command/usercheckpw.go
@@ -81,9 +81,9 @@ func (c *UserCheckPwCommand) Run(args []string) int {
 	}
 
 	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)
+		input, err := c.UI.AskSecret(fmt.Sprintf("Enter password for %s:", address))
+		if err != nil {
+			fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
 			return 1
 		}
 
diff --git a/cmd/mailfull/command/userdel.go b/cmd/mailfull/command/userdel.go
index b19c365..9e2d2b4 100644
--- a/cmd/mailfull/command/userdel.go
+++ b/cmd/mailfull/command/userdel.go
@@ -59,6 +59,11 @@ func (c *UserDelCommand) Run(args []string) int {
 		return 1
 	}
 
+	if userName == "postmaster" {
+		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] Cannot delete postmaster.\n")
+		return 1
+	}
+
 	if err := repo.UserRemove(domainName, userName); err != nil {
 		fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
 		return 1
diff --git a/cmd/mailfull/command/userpasswd.go b/cmd/mailfull/command/userpasswd.go
index 5f5be57..ea568d8 100644
--- a/cmd/mailfull/command/userpasswd.go
+++ b/cmd/mailfull/command/userpasswd.go
@@ -81,14 +81,14 @@ func (c *UserPasswdCommand) Run(args []string) int {
 	}
 
 	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)
+		input1, err := c.UI.AskSecret(fmt.Sprintf("Enter new password for %s:", address))
+		if err != nil {
+			fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
 			return 1
 		}
-		input2, err2 := c.UI.AskSecret("Retype new password:")
-		if err2 != nil {
-			fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err2)
+		input2, err := c.UI.AskSecret("Retype new password:")
+		if err != nil {
+			fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
 			return 1
 		}
 		if input1 != input2 {
@@ -100,9 +100,9 @@ func (c *UserPasswdCommand) Run(args []string) int {
 
 	hashedPassword := mailfull.NeverMatchHashedPassword
 	if rawPassword != "" {
-		str, errHash := ssha.Generate(rawPassword, 4)
-		if errHash != nil {
-			fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", errHash)
+		str, err := ssha.Generate(rawPassword, 4)
+		if err != nil {
+			fmt.Fprintf(c.UI.ErrorWriter, "[ERR] %v\n", err)
 			return 1
 		}
 		hashedPassword = str
diff --git a/generateconfig.go b/generateconfig.go
index a2cc75f..01af7ba 100644
--- a/generateconfig.go
+++ b/generateconfig.go
@@ -45,7 +45,7 @@ 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_session_cache_database = btree:/var/lib/postfix/smtpd_scache
 smtpd_tls_mandatory_protocols = !SSLv2, !SSLv3
 
 smtp_tls_security_level = may
diff --git a/repository.go b/repository.go
index a1e27dd..187c997 100644
--- a/repository.go
+++ b/repository.go
@@ -126,10 +126,10 @@ func OpenRepository(basePath string) (*Repository, error) {
 	for {
 		configDirPath := filepath.Join(rootPath, DirNameConfig)
 
-		fi, errStat := os.Stat(configDirPath)
-		if errStat != nil {
-			if errStat.(*os.PathError).Err != syscall.ENOENT {
-				return nil, errStat
+		fi, err := os.Stat(configDirPath)
+		if err != nil {
+			if err.(*os.PathError).Err != syscall.ENOENT {
+				return nil, err
 			}
 		} else {
 			if fi.IsDir() {
diff --git a/version.go b/version.go
index 76908b4..51658b0 100644
--- a/version.go
+++ b/version.go
@@ -1,4 +1,4 @@
 package mailfull
 
 // Version is a version number.
-const Version = "0.0.2"
+const Version = "v0.0.3"