in reply to Most of the email spam I get is:
Not really perl-related but the best way of stopping spam is at the MTA level with RBLs (Runtime Black Lists.) These are lists of the IP addresses of confirmed spammers and other machines which should not be sending mail such as open relays, home machines, etc. Some RBLs are rather trigger-happy and add blacklist legitimate users sometimes but the following, which I use with postfix, are considered pretty reputable:
I used to get 200-300 spam messages a day. Now thanks to these methods, I get 1 or 2.