diff --git a/smtpd/filestore.go b/smtpd/filestore.go
index 50f6bf0..221ccbb 100644
--- a/smtpd/filestore.go
+++ b/smtpd/filestore.go
@@ -72,7 +72,42 @@ func (ds *FileDataStore) MailboxFor(emailAddress string) (Mailbox, error) {
 
 // AllMailboxes returns a slice with all Mailboxes
 func (ds *FileDataStore) AllMailboxes() ([]Mailbox, error) {
-	return nil, nil
+	mailboxes := make([]Mailbox, 0, 100)
+	infos1, err := ioutil.ReadDir(ds.mailPath)
+	if err != nil {
+		return nil, err
+	}
+	// Loop over level 1 directories
+	for _, inf1 := range infos1 {
+		if inf1.IsDir() {
+			l1 := inf1.Name()
+			infos2, err := ioutil.ReadDir(filepath.Join(ds.mailPath, l1))
+			if err != nil {
+				return nil, err
+			}
+			// Loop over level 2 directories
+			for _, inf2 := range infos2 {
+				if inf2.IsDir() {
+					l2 := inf2.Name()
+					infos3, err := ioutil.ReadDir(filepath.Join(ds.mailPath, l1, l2))
+					if err != nil {
+						return nil, err
+					}
+					// Loop over mailboxes
+					for _, inf3 := range infos3 {
+						if inf3.IsDir() {
+							mbdir := inf3.Name()
+							mbpath := filepath.Join(ds.mailPath, l1, l2, mbdir)
+							mb := &FileMailbox{store: ds, dirName: mbdir, path: mbpath}
+							mailboxes = append(mailboxes, mb)
+						}
+					}
+				}
+			}
+		}
+	}
+
+	return mailboxes, nil
 }
 
 // A Mailbox manages the mail for a specific user and correlates to a particular
diff --git a/smtpd/filestore_test.go b/smtpd/filestore_test.go
new file mode 100644
index 0000000..49ff409
--- /dev/null
+++ b/smtpd/filestore_test.go
@@ -0,0 +1,117 @@
+package smtpd
+
+import (
+	"github.com/stretchrcom/testify/assert"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"testing"
+	"time"
+)
+
+var mailboxNames = []string{"abby", "bill", "christa", "donald", "evelyn"}
+
+func TestFSAllMailboxes(t *testing.T) {
+	fds := setupDataStore()
+	defer teardownDataStore(fds)
+
+	mboxes, err := fds.AllMailboxes()
+	assert.Nil(t, err)
+	assert.Equal(t, len(mboxes), 5)
+}
+
+// setupDataStore will build the following structure in a temporary
+// directory:
+//
+// /tmp/inbucket?????????
+// └── mail
+//     ├── 53e
+//     │   └── 53e11e
+//     │       └── 53e11eb7b24cc39e33733a0ff06640f1b39425ea
+//     │           ├── 20121024T164239-0000.gob
+//     │           ├── 20121024T164239-0000.raw
+//     │           ├── 20121025T164239-0000.gob
+//     │           └── 20121025T164239-0000.raw
+//     ├── 60c
+//     │   └── 60c596
+//     │       └── 60c5963a56da1425f133d28166ca4fe70dcb25f5
+//     │           ├── 20121024T164239-0000.gob
+//     │           ├── 20121024T164239-0000.raw
+//     │           ├── 20121025T164239-0000.gob
+//     │           └── 20121025T164239-0000.raw
+//     ├── 88d
+//     │   └── 88db92
+//     │       └── 88db9292c772b38311e1778f6f6b18216443abf0
+//     │           ├── 20121024T164239-0000.gob
+//     │           ├── 20121024T164239-0000.raw
+//     │           ├── 20121025T164239-0000.gob
+//     │           └── 20121025T164239-0000.raw
+//     ├── c69
+//     │   └── c692d6
+//     │       └── c692d6a10598e0a801576fdd4ecf3c37e45bfbc4
+//     │           ├── 20121024T164239-0000.gob
+//     │           ├── 20121024T164239-0000.raw
+//     │           ├── 20121025T164239-0000.gob
+//     │           └── 20121025T164239-0000.raw
+//     └── e76
+//         └── e76cef
+//             └── e76ceff3c47adb10f62b1acd7109f88fbd5e9ca7
+//                 ├── 20121024T164239-0000.gob
+//                 ├── 20121024T164239-0000.raw
+//                 ├── 20121025T164239-0000.gob
+//                 └── 20121025T164239-0000.raw
+func setupDataStore() *FileDataStore {
+	// Build fake SMTP message for delivery
+	testMsg := make([]byte, 0, 300)
+	testMsg = append(testMsg, []byte("To: somebody@host\r\n")...)
+	testMsg = append(testMsg, []byte("From: somebodyelse@host\r\n")...)
+	testMsg = append(testMsg, []byte("Subject: test message\r\n")...)
+	testMsg = append(testMsg, []byte("\r\n")...)
+	testMsg = append(testMsg, []byte("Test Body\r\n")...)
+
+	path, err := ioutil.TempDir("", "inbucket")
+	if err != nil {
+		panic(err)
+	}
+	mailPath := filepath.Join(path, "mail")
+	ds := &FileDataStore{path: path, mailPath: mailPath}
+
+	for _, name := range mailboxNames {
+		mb, err := ds.MailboxFor(name)
+		if err != nil {
+			panic(err)
+		}
+		// Create day old message
+		date := time.Now().Add(-24 * time.Hour)
+		msg := &FileMessage{
+			mailbox:  mb.(*FileMailbox),
+			writable: true,
+			Fdate:    date,
+			Fid:      generatePrefix(date) + "-0000",
+		}
+		msg.Append(testMsg)
+		if err = msg.Close(); err != nil {
+			panic(err)
+		}
+
+		// Create current message
+		date = time.Now()
+		msg = &FileMessage{
+			mailbox:  mb.(*FileMailbox),
+			writable: true,
+			Fdate:    date,
+			Fid:      generatePrefix(date) + "-0000",
+		}
+		msg.Append(testMsg)
+		if err = msg.Close(); err != nil {
+			panic(err)
+		}
+	}
+	return ds
+}
+
+func teardownDataStore(ds *FileDataStore) {
+	if err := os.RemoveAll(ds.path); err != nil {
+		panic(err)
+	}
+}