Here is a guide on getting Email services running on Ubuntu Intrepid. I used Postfix for core services (SMTP wtih TLS and SASL) and Dovecot for fast IMAP and POP3. This tutorial has been tested on a bare bones Ubuntu 8.10 slice from Slicehost.
I recently spent some quality time (read: 6 hours) setting up email services on my server with Ubuntu Hardy. Here’s a very quick mini-tutorial of the steps that got me up and running with IMAP, SMTP, TLS, and POP3.