A few months ago, I read about PeerGuardian, a special windows program that blocks traffic to and from certain hosts that are known to be associated with law enforcement agencies and the like or just plain old spyware and malware.
That's cool, except that today I discovered that the reason my Outlook can't download any of my dreamhost mail is because the mail server is blocked by this program. My theory is that someone must have sent a crapload of spam from a dreamhost mail domain, and that earned it an entry on the PG block list.
The real problem is that el cheapo dreamhost maps all your mail domains to the same host. mail.kendeeter.com, mail.test.kendeeter.com, etc, all point to the same IP, and thus all get blocked by the same rule.
Lame.