May 29, 2004

Greylisting via Postfix

I've been exploring a new (to me) idea called Greylisting, which is kind of a middle ground between blacklisting (denying) and whitelisting (accepting) mail sent to a server. Basically, what this does is instruct the system trying to send you mail to 'try again later'. Legitimate mails will be retried at whatever interval the other system is set to, but most junk mails won't even try resending, effectively blocking those.

The postfix implementation of this seems a bit spotty currently, but may improve once a few more folks start playing with it. However, at least one person questions its effectiveness based on the amount of spam hitting his Hotmail account, and that fact that those servers are generally hard to reach anyway.

Posted by Jim at May 29, 2004 10:07 PM | TrackBack