Imapsrv

This is an IMAP server written in Go. It is a work in progress.

Demo

In the demo subdirectory there are several implementation examples available.

$ go run ./demo/basic/main.go

You can connect to this server using telnet or netcat. For example:

$ nc -C localhost 1193
* OK IMAP4rev1 Service Ready
10 LOGIN test anypassword
10 OK LOGIN completed
20 CAPABILITY
* CAPABILITY IMAP4rev1
20 OK CAPABILITY completed
30 SELECT inbox
* 8 EXISTS
* 4 RECENT
* OK [UNSEEN 4] Message 4 is first unseen
* OK [UIDVALIDITY 1] UIDs valid
* OK [UIDNEXT 9] Predicted next UID
30 OK SELECT completed
40 LOGOUT
* BYE IMAP4rev1 Server logging out
40 OK LOGOUT completed

Developing

The server is not fully operational on its own. It requires a mailstore and an authentication mechanism.

It defines an interface in mailstore.go which describes the service it needs from a Mailstore. For example a Mailstore could serve its data from: database, filesystem, maildir, etc... At the moment only one mailstore can be used at the same time.

To add a new IMAP command the usual steps are:

1. Add the command to parser.go
2. Add the command and its client interaction to commands.go
3. Put the main functionality in session.go.

Current state

IMAP (RFC 3501)

Client Commands - Any state

• CAPABILITY command - in progress
• NOOP command
• LOGOUT command

Client Commands - Not-Authenticated State

• STARTTLS command
• AUTHENTICATE command
• LOGIN command

Client Commands - Authenticated State

• SELECT command
• EXAMINE command
• CREATE command
• DELETE command
• RENAME command
• SUBSCRIBE command
• UNSUBSCRIBE command
• LIST command
• LSUB command
• STATUS command
• APPEND command

Client Commands - Selected State

• CHECK command
• CLOSE command
• EXPUNGE command
• SEARCH command
• FETCH command - in progress
• STORE command
• COPY command
• UID command

Server responses

• OK response
• NO response
• BAD response
• PREAUTH response
• BYE response

License

3-clause BSD