Spam, the bane, the blight, the plague, the scourge of the internet!
It's getting harder and harder to avoid. Sure, you can use the tactic of signing up for a free Yahoo or Hotmail email account to use for non business or non personal email. (So, what would we call this 3rd category? Quasi-Nuisance email??) However, this doesn't prevent you from receiving all sorts of fun spam email. Trust me.
If you have your email on your web site, you can also fall victim to email harvesters who spider your web site looking for email addresses to spam. (There are ways to encrypt your email address to trick these spiders, but *that's* another tip for another week!)
Mailwasher is an anti-spam software which has received some rave reviews. Not only will it notify you if an email is spam, possibly spam, or a virus, but it can also delete the email before it's downloaded, and bounce the message back to the sender so that the spammer will think your email address is invalid (and hopefully, leave you alone!)
Some caveats; it only runs on Windows, and doesn't yet handle web email (such as Hotmail or AOL), but the web site promises an upgrade for these features within another month or so.
Is it free? Well, yes, and no. The web site asks for a voluntary donation between $3 and $20 for personal use.
Two other interesting anti-spam web sites are Arachnoid's Anti-Spam Page , and SpamFaq.net
Hope this helps! Feel free to email Lesley if you run into any problems.