Okay, I think I have this under control. Apparently verizon is not using VRFY but a strategy similar to this one:
http://jeremy.kister.net/code/perl/vrfy.pl And thus they determine if the address in the return-path of the envelope (ie not the From or Reply-To headers listed in the message) can accept e-mail. If you fish around in your qmail queue, the return-path is in the /var/qmail/queue/info folders. I was getting a lot of this: deferral: Connected_to_206.46.170.12_but_sender_was_rejected./Remote_host_said:_450_Requested_mail_action_not_taken-Try_later:sc011pub.verizon.net But the only messages verizon rejected from my server turned out to be messages with an invalid return-path. They were valid nonspam messages with valid Reply-to and From headers, but they had been auto-generated by perl scripts or php scripts on the system. The best attempts of these scripts to provide Return Path resulted in bogus addresses like [EMAIL PROTECTED] With some small adjustments in the way the scripts invoke sendmail (or, you know, the qmail sendmail alias), those scripts are now supplying valid return-path addresses for the envelope. eg, modify sendmail_path in php.ini to change the default: sendmail_path = "/usr/sbin/sendmail -f [EMAIL PROTECTED] -t -i" Hope this helps! -tom PS - I have hacked my qmail to include chkusr, which rejects addresses not handled by vpopmail. I strongly recommend this patch, since it significantly reduces the amount of spam that even makes it into the queue. This patch may be altering my responses to verizon, so if you don't have it your mileage may vary...
