Ok after doing some research and based on my needs I think the following best meets my needs: Exim+Cyrus IMAP+Squirrel Mail+Using shared BerkeleyDB files for domains/aliases/authentication.
The only thing I think I may have problems with is cyrus+berkeley(I haven't been able to find much online). Anyone doing something similar? --- Cyrus Home Page: http://asg.web.cmu.edu/cyrus Cyrus Wiki/FAQ: http://cyruswiki.andrew.cmu.edu List Archives/Info: http://asg.web.cmu.edu/cyrus/mailing-list.html
