[Techtalk] imap server

[Shirrell]

We have a small network of linux, pc/windows, and sun sparc/solaris which
we have isolated from the world -- the server has most services turned off.
We would like to open it up slightly so that our sales staff could dial in
to pick up email.  The plan is to put up an imap server, probably on a
small PC running red hat.  Access would come through the router that
controls the cable modem.  The question is which IMAP server would be
adequate and yet not too difficult to install and configure. 

Any suggestions would be appreciated,
shirrell at pstat.com