go-imap

An IMAP4rev1 library written in Go. It can be used to build a client and/or a server and supports UTF-7.

go get github.com/emersion/go-imap

Why?

Other IMAP implementations in Go:

• Require to make many type assertions or conversions
• Are not idiomatic or are ugly
• Are not pleasant to use
• Implement a server xor a client, not both
• Don't implement unilateral updates (i.e. the server can't notify clients for new messages)

Implemented commands

This package implements all commands specified in the RFC.

Command	Client	Client tests	Server	Server tests
CAPABILITY	✓	✓	✓	✓
NOOP	✓	✓	✓	✓
LOGOUT	✓	✓	✓	✓
AUTHENTICATE	✓	✓	✓	✓
LOGIN	✓	✓	✓	✓
STARTTLS	✓	✓	✓	✗
SELECT	✓	✓	✓	✓
EXAMINE	✓	✓	✓	✗
CREATE	✓	✓	✓	✓
DELETE	✓	✓	✓	✓
RENAME	✓	✓	✓	✓
SUBSCRIBE	✓	✓	✓	✓
UNSUBSCRIBE	✓	✓	✓	✓
LIST	✓	✓	✓	✓
LSUB	✓	✓	✓	✗
STATUS	✓	✓	✓	✓
APPEND	✓	✓	✓	✗
CHECK	✓	✓	✓	✗
CLOSE	✓	✓	✓	✗
EXPUNGE	✓	✓	✓	✗
SEARCH	✓	✓	✓	✗
FETCH	✓	✓	✓	✗
STORE	✓	✓	✓	✗
COPY	✓	✓	✓	✗
UID	✓	✗	✓	✗

IMAP extensions

Commands defined in IMAP extensions are available in other packages.

• COMPRESS
• SPECIAL-USE
• MOVE

Usage

Client

package main

import (
	"log"

	"github.com/emersion/go-imap/client"
	imap "github.com/emersion/go-imap/common"
)

func main() {
	log.Println("Connecting to server...")

	// Connect to server
	c, err := client.DialTLS("mail.example.org:993", nil)
	if err != nil {
		log.Fatal(err)
	}
	log.Println("Connected")

	// Don't forget to logout
	defer c.Logout()

	// Login
	if err := c.Login("username", "password"); err != nil {
		log.Fatal(err)
	}
	log.Println("Logged in")

	// List mailboxes
	mailboxes := make(chan *imap.MailboxInfo)
	go (func () {
		err = c.List("", "%", mailboxes)
	})()

	log.Println("Mailboxes:")
	for m := range mailboxes {
		log.Println("* " + m.Name)
	}

	if err != nil {
		log.Fatal(err)
	}

	// Select INBOX
	mbox, err := c.Select("INBOX", false)
	if err != nil {
		log.Fatal(err)
	}
	log.Println("Flags for INBOX:", mbox.Flags)

	// Get the last 4 messages
	seqset, _ := imap.NewSeqSet("")
	seqset.AddRange(mbox.Messages - 3, mbox.Messages)

	messages := make(chan *imap.Message, 4)
	err = c.Fetch(seqset, []string{"ENVELOPE"}, messages)
	if err != nil {
		log.Fatal(err)
	}

	for msg := range messages {
		log.Println(msg.Envelope.Subject)
	}

	log.Println("Done!")
}

Server

package main

import (
	"log"

	"github.com/emersion/go-imap/server"
	"github.com/emersion/go-imap/backend/memory"
)

func main() {
	// Create a memory backend
	bkd := memory.New()

	// Create a new server
	s, err := server.Listen(":3000", bkd)
	if err != nil {
		log.Fatal(err)
	}

	// Since we will use this server for testing only, we can allow plain text
	// authentication over unencrypted connections
	s.AllowInsecureAuth = true

	log.Println("Server listening at", s.Addr())

	// Do something else to keep the server alive
	select {}
}

You can now use telnet localhost 3000 to manually connect to the server.

License

MIT