When it's working, Em@ilCRX does a better job with spam than anything I've tried, but I am experience problems running it on my computer (Dual 450Mhz G4, 10.4.8) with Eudora as my mail agent.

the program periodically eats all my CPU cycles, taking many minutes even to come to the foreground. This occurs even when running in Safe Mode, so it does not appear to be due to third party software conflicts.

If it runs for you, then great, because it does a superb job. I don't know what the sourced of my problem is, but I don't appear to be the only one.

Be prepared to do a lot of setup yourself. The program is not particularly newbie-friendly, and the manual does not explain things like "Run Aging", nor are these elements customizable at this point.

that said, there is an active and helpful discussion forum at http://hendricom.com and the developer is quite active and engaged.