Howdy list, I've been contemplating this spam fighting technique, and I was wondering if I could get this list's opinion on it. (I don't THINK that qpsmtpd does this already...)
Anyway, the background behind the idea is this: I and my company use TMDA to help us virtually eliminate spam in our (and our customer's) inboxes. We've noticed that about 70% of the confimation requests sent out for messages that end up in our pending queues BOUNCE because the sender address or from address was bogus. It would be great if we could stop these messages from getting to the pending queue in the first place by doing a reverse SMTP lookup on the envelope sender (and possibly the FROM header) at message transmission time. I'd like to implement this as an SMTP probe to the remote server in the form of a "RCPT TO:" check. Obviously SMTP servers like qmail don't ever deny incoming message when sent a "RCPT TO:", but that's ok. I only plan to block the incoming email if the SMTP probe definitively fails at "RCPT TO:". What does this list think about such an idea? I know that many people are vehemently opposed to even doing a reverse DNS lookup on incoming mail, much less a full SMTP probe. However, I'm not too worried about it. I think it's a good idea that would reduce possibly up to 50% of our customer's spam RELIABLY with virtually no lost legitimate mail. Thanks for the bandwidth. I'm looking forward to hearing any opinions about this idea. -- Jesse Guardiani, Systems Administrator WingNET Internet Services, P.O. Box 2605 // Cleveland, TN 37320-2605 423-559-LINK (v) 423-559-5145 (f) http://www.wingnet.net We are actively looking for companies that do a lot of long distance faxing and want to cut their long distance bill by up to 50%. Contact [EMAIL PROTECTED] for more info.
