Well, I finally figured out why tarpitting isn't deterring the SPAMmers hitting my server. Every request appears to come from a different IP. Over 3000 just today. This is why we need Greylisting in courier. We need the equivalent of postgrey, which according to it's home page:

"When a request for delivery of a mail is received by Postfix via SMTP, the triplet CLIENT_IP / SENDER / RECIPIENT is built. If it is the first time that this triplet is seen, or if the triplet was first seen, less than 5 minutes ago, then the mail gets rejected with a temporary error. Hopefully spammers or viruses will not try again later, as it is however required per RFC."

This has gotten bad to the point of making courier unusable - the spammers are hitting up to the MAX connections, and no courier feature slows them down. My users can't send mail, because any new threads I make available are taken up by the spammers.

Any thoughts?

Thx!

-steve j