Blocking spam is really not the most effective way to slow spam down. Preventing spam is much more effective. If you are receiving lots of spam on a particular email addr. I recommend that you:
1. Just create a new addr. and let everyone who you want to have your addr. know that you have changed it.
2. When entering your email addr. on a web site create an email account just for that site, for example ebay. You will get lots of spam over time when using an email addr. on ebay and many others of course.
3. Use a disposable address on web sites that want you to enter your address to; say download software for example.
4. Never, ever post your email address on your web site or any other site. You are just asking for spam when you post your email addr. on a web site. Instead use a form that your visitors will enter information in to and will mask your email from being extracted by one of those nasty, blood sucking email bots.
You may want to give this script a try, or something simular.
karlcore
5. Never reply to an email to be taken off a mailing list. This just tells a spammer that they have reached a valid addr.
6. As far as a good way to configure spam assassin; well have you seen how many different ways there are to spell Viagra lately? I say forget about trying to block it and just try to prevent it the best you can.
Good luck -Jason
PS I hate spam