Hi, Is there any kind of plugin or patch for spamassassin that will allow me to selectively turn on GREYLISTing for certain user accounts?
When I say greylist I mean: All e-mail coming into them is bounced with a temporary error the first time, and then accepted the second time. If accepted (ie sent a second time) it is then put in a database of valid e-mail accounts for the next 60 days (or until another e-mail is received).
This has the potential to greatly reduce spam since spammers don't usually try to send mail again, however I don't want to roll this out on a server wide setup, but rather would like to do it on a per-user basis.
Greylisting has to kick in earlier than SpamAssassin. Have you looked at milter-greylist? http://hcpnet.free.fr/milter-greylist/ It allows you to choose which users use grey listing.
I think you're suggesting, however, that it should be possible to set something up that lets users choose whether to be using grey-listing. You might be able to extend Maia Mailguard (http://www.maiamailguard.com/) to do that.
FWIW, I'm running milter-greylist on my account on a busy system. I get almost zero spam coming through. The downside is that some servers may take several hours before retrying. Most retry in about 30 minutes. I generally think that's a fair trade off.
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Steve
