Spam Bot Blocker is a free utility that obfuscated (scrambles) your email address so that you can post it to your website with less risk of it being harvested by spam bots.
SpamButcher is an advanced anti-spam filter. Its spam blocker can stop 98% of spam. Every few minutes it checks for new messages in your inbox. If it finds any spam, it's moved to a holding area for later examination.
SpamWeed - Email Spam Filter and Remover Software. Using Spamweed means your inbox won't be full of junk email spam, Spamweed uses a Bayesian filter to detect which email is real or spam.
Spam Blocker blocks unwanted messages on the mail server. Saves traffic and delivers from viewing annoying e-mail advertising. Spam Blocker works with several mailboxes and allows configuring user setting for blocking spam.
Anti-Spam Blacklist Thing lets you check to see if a given IP address or hostname is on one of up to 20 different anti-spam blacklists. Anti-Spam Blacklist Thing is provided by SpamButcher completely free of charge.