Mac Geekery

Now we delve into the obscure: IMAP over Telnet. Huzzah.

IMAP really, really, really wants to be done with client software. While it does use “normal” text it is quite text-intensive, displays a lot of information as it goes, is very slow to navigate by hand, and generally un-fun. Yet, sometimes you need to do it, so here’s how.

Open the Connection

All IMAP command start with “# “ (a number, any number, and a space). It can get annoying. Also, unlike both SMTP and POP, IMAP logins are on one line rather than a modal session.

$ telnet mail.mac.com imap4
Trying 17.250.248.64...
Connected to mail.mac.com.
Escape character is '^]'.
* OK Netscape Messaging Multiplexor ready
1 LOGIN username password
1 OK User logged in

List the Mailboxes

IMAP, unlike POP, is based on the concept of mailboxes, so let’s get a list.

1 LIST """%"
* LIST (\NoInferiors) "/" INBOX
* LIST (\HasNoChildren) "/""Deleted Messages"
* LIST (\HasNoChildren) "/" Drafts
* LIST (\HasNoChildren) "/""Sent Messages"
* LIST (\HasNoChildren) "/" Trash
1 OK Completed

Open the Mailbox

Unless filtered or moved, mail lands in the INBOX folder by default, so we’ll check that one.

1 select INBOX
* FLAGS (\Answered \Flagged \Draft \Deleted \Seen NotJunk Junk JunkRecorded Forwarded Redirected NonJunk $NotJunk $Junk)
* OK [PERMANENTFLAGS (\Answered \Flagged \Draft \Deleted \Seen NotJunk Junk JunkRecorded Forwarded Redirected NonJunk $NotJunk $Junk \*)]  
* 758 EXISTS
* 0 RECENT
* OK [UNSEEN 2]  
* OK [UIDVALIDITY 1015777771]  
1 OK [READ-WRITE] Completed

FLAGS tells you what flags the server supports for messages in this box. EXISTS tells you the number of messages in the box.

Get a Message

Here’s where it gets fun.

1 fetch 1 all
* 1 FETCH (FLAGS (\Seen) INTERNALDATE "18-Sep-2004 10:55:23 -0700" RFC822.SIZE 5033 ENVELOPE ("Sat, 18 Sep 2004 19:39:56 +0200""Re: Converting an Absolute path to a relative path?" (("someone" NIL "someone""somewhere.net")) ((NIL NIL "cocoa-dev-bounces+someone=somewhere.com""lists.apple.com")) (("someone" NIL "someone""somewhere.net")) (("=?iso-8859-1?Q?St=E9phane?= Sudre" NIL "someone""somewhere.fr")(NIL NIL "cocoa-dev""lists.apple.com")) NIL NIL "<EAE0A136-0997-11D9-A07A-003065B01042@somewhere.fr>""<a0611040dbd7223277580@[192.168.0.4]>"))
1 OK Completed

Yes, those are headers. No, they don’t get prettier. Now that we know this is the one we want (if not, knock yourself out hunting for it), we get it.

1 fetch 1 body
* 1 FETCH (BODY ("TEXT""PLAIN" ("FORMAT""flowed""CHARSET""iso-8859-1") NIL NIL "QUOTED-PRINTABLE" 946 24))
1 OK Completed

No, wait, that’s not right. Where’s the message? Oh, right, I have to specify that I want the text of the body, not just a description of it. Remember, I’m human, not a client program.

001 fetch 1 body[text]
* 1 FETCH (FLAGS (\Seen) BODY[TEXT] {946}
At 19:26 Uhr +0200 18.09.2004, St=E9phane Sudre wrote:
>Did I reinvent the wheel or is there really not=20
>a method in NSString which allows to convert an=20
>absolute path to a relative one provided a=20
>reference path?
...
001 OK Completed

Mark for Deletion

IMAP is more like a transactional database than a mailbox in how it handles deletion. First, you set a flag on a message (or ten) to have it deleted and then, when you’re sure, you commit those changes with an EXPUNGE command. So, knowing the ID of the message above you can mark it deleted (or read, or flagged, or whatever) by setting the Deleted flag:

0 store 3 +FLAGS (\Deleted)
* 3 FETCH (FLAGS (\Deleted))
0 OK Completed

If you make a mistake, replace +FLAGS with -FLAGS to remove the flag.

When you’re sure you made no typos, flush ‘em.

0 expunge
* 3 EXPUNGE
* 701 EXISTS
* 1 RECENT
0 OK Completed

And Dismount

1 logout
* BYE LOGOUT received
1 OK Completed
Connection closed by foreign host.

Enjoy, I know I won’t.