A word of advice: running your own web server at home is pretty trivial, but running a mail server is not. For a mail server running your home page and maybe a few neat perl applications, uptime isn't really crucial but for a mail server it is. If your box goes down while you're on vacation for a two weeks, then you'll lose two weeks worth of email. Also, configuring a mail server like sendmail is far from trivial... (been there, tried that :)

stephen's approach (above) of setting up an internal mail server and use fetchmail to pull mail from a POP account is a lot easier to set up. Assuming you're using a decent ISP it will also be hell of a lot more reliable.

No one has mentioned it yet, but Mail::Audit is pretty cool for user-level mail filters. It's a procmail replacement which lets you write perl programs to sort and/or reject mails. Nice, because that means I will never have to use procmail ever again.

See also: A Beginner's Guide to Using Mail::Audit and Mail::SpamAssassin

Cheers,
--Moodster