Good tutorial for setting up SMTP/POP3 on Debian?

Bryan Duxbury wrote:

I've been looking for a good tutorial on how to set up a mail server for my VPS (rimuhosting) for my website (www.greekadmin.com). I've been able to get a basic SMTP server up (postfix or exim) that can successfully send emails from my Rails apps.

The problem I'm running into now is that I'd like to set up some email addresses for me and my partner to check and send email via standard mail clients. I can't seem to find a good tutorial that describes in exquisite detail what I need to do to get outgoing email from any address if it originates on the server, but also allow authenticated users to send email from off-server.

If anyone could point me in the right direction, I'd really appreciate it.   

Ezra's "The Perfect Rails/Debian/Lighttpd Stack..." covers setting up SMTP (Postfix) and POP3 (QPopper):

http://brainspl.at/rails_stack.html