There was this message last year about IMAP, though nothing else except
for a similar question to yours in 1999.

Note that I believe it would take a bit of work to properly integrate
IMAP into Celeste, in case that is what you were thinking of doing with
it.

Mike

_____
Date: Fri, 16 Jun 2000 17:14:07 -0500
From: Les Tyrrell <tyrrell at canis.uiuc.edu>
Subject: IMAP client framework alpha release
To: squeak at cs.uiuc.edu

Well, it looks like it is running fine and can be used by others so at
this point
I'm releasing my IMAP client framework as a possible CampSmalltalk
sub-project.
This was built within the context of SmallWalker's Network Clients
framework,and
I'm including files for that just in case I've changed something in them
that doesn't
immediately come to mind.

See http://oasis.canis.uiuc.edu:8080/EMail for details.  Remember, this
was built
in VisualWorks so if you want to use it in Squeak there will be some
potentially
non-trivial effort involved.  This is still an early alpha framework, so
expect
there to be significant changes in later releases.  Still, it would be
good to know
what problems people might run into trying to use it in Squeak.  Let me
know and
I'll try to accomodate those uses.

Good Luck!

- les