Spam Fu Fighting

I’ve reached a breaking point with Spam. I signed up with SpamCop, but reporting spams doesn’t seem to be as effective as it used to be. (Or maybe more spammers have my address now.) I’ve been looking at various options for spam management, and have come up with two general classes of deterrent:

  1. Client-side tools: these work by scanning your email account and removing spam, and then allowing your mail program to retrieve the remaining mail. The advantage to these is that they’re easy to use. The disadvantage is that they work best with a single email account. Among the most regarded of these for Mac OS X is SpamFire, which I’m currently evaluating.
  2. Server-side tools: these run right on the mail server, and filter mail as it arrives. They tend to be harder to configure and use, and you have to administer your own mail server to be able to make use of them. The best tools appear to be UNIX-only, due to the fact that it has a very flexible infrastructure for handling mail. On the upside, they’re more efficient and can handle spam filtering for all the accounts on the server.

Though I really like the ease of use of the client-side solutions, I’m gradually coming to the conclusion that I may be best off setting up a mail server at the house and pointing my domains there. So, technical questions for those of you who are good at this sort of thing:

I assume a Pentium 133 running Linux would be capable of handling mail server duties. How difficult is it to set up a POP3/IMAP server on a Linux box? To get mail delivered to it, would I need to do anything other than altering the MX records for the affected domains to point to the appropriate machine? Can I use DynDNS to resolve that machine’s actual IP address, or is something trickier required? Anything else I should know?