go-imap
An IMAP4rev1 library written in Go. It can be used to build a client and/or a server.
Usage
Client 
package main
import (
"log"
"github.com/emersion/go-imap/client"
"github.com/emersion/go-imap"
)
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, 10)
done := make(chan error, 1)
go func () {
done <- c.List("", "*", mailboxes)
}()
log.Println("Mailboxes:")
for m := range mailboxes {
log.Println("* " + m.Name)
}
if err := <-done; 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
from := uint32(1)
to := mbox.Messages
if mbox.Messages > 3 {
// We're using unsigned integers here, only subtract if the result is > 0
from = mbox.Messages - 3
}
seqset := new(imap.SeqSet)
seqset.AddRange(from, to)
messages := make(chan *imap.Message, 10)
done = make(chan error, 1)
go func() {
done <- c.Fetch(seqset, []imap.FetchItem{imap.FetchEnvelope}, messages)
}()
log.Println("Last 4 messages:")
for msg := range messages {
log.Println("* " + msg.Envelope.Subject)
}
if err := <-done; err != nil {
log.Fatal(err)
}
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
be := memory.New()
// Create a new server
s := server.New(be)
s.Addr = ":1143"
// Since we will use this server for testing only, we can allow plain text
// authentication over unencrypted connections
s.AllowInsecureAuth = true
log.Println("Starting IMAP server at localhost:1143")
if err := s.ListenAndServe(); err != nil {
log.Fatal(err)
}
}You can now use telnet localhost 1143 to manually connect to the server.
Extensions
Support for several IMAP extensions is included in go-imap itself. This includes:
Support for other extensions is provided via separate packages. See below.
Extending go-imap
Extensions
Commands defined in IMAP extensions are available in other packages. See the wiki to learn how to use them.
Server backends
Related projects
- go-message - parsing and formatting MIME and mail messages
- go-msgauth - handle DKIM, DMARC and Authentication-Results
- go-pgpmail - decrypting and encrypting mails with OpenPGP
- go-sasl - sending and receiving SASL authentications
- go-smtp - building SMTP clients and servers
License
MIT