Evan Platt wrote: > At 12:23 PM 1/5/2006, you wrote: > >> Well, bounce warnings are in fact valid email.. >> >> For example, if you accidentally sent mail to "[EMAIL PROTECTED]" >> you'd get a >> bounce back, and you'd probably want to know about it. > > > Ok, I should have clarified.. There's a FEW I'm seeing with the null > return path. Not all. > >> You definitely do not want to reject emails with this at SMTP time. >> There's a >> whole RBL out there for people who do this (RFCI's DSN list). >> >> Among other things, you'll really piss off system admins of other >> sites who >> really are sending you valid bounce messages and you force the message to >> double-bounce into their postmaster box. >> >> You'll also be in flagrant violation of RFC 821/2821 which says you >> MUST accept >> mail with a null return path. > > > Ok, appreciate the suggestions. I think a better flag that seems to be a > hit is: > > From: [EMAIL PROTECTED] - I see no valid e-mails from this.
Same thing... Most DSN messages come back with a null return path and an empty From: header. Such messages get substituted with MAILER-DAEMON. Really, your problem is how to deal with blowback, not how to refuse all the floods of bounce messages at SMTP time. Suggestion to start with: Publish a SPF record. While SPF doesn't do much for stopping spam, it does make it more difficult for spam/viruses to forge your domain, which in turn results in less blowback at your site. >From there, start looking into using SA rules to tag/autotrash the bounce messages from joe-job floods and virus floods.
