Noel Jones: > Also sounds as if you don't have a valid recipient list for > these customers. Not OK. Your queue is likely filled with > lots of undeliverable mail to unknown recipients, and > undeliverable bounces to bogus senders, plus you're sending > out backscatter to innocent parties. This will get you > blacklisted. > > The solution is two steps. > > First, if you can't get a valid recipient list you can use > address verification so that you don't accept mail to bogus > users in the first place. This is really important. > http://www.postfix.org/ADDRESS_VERIFICATION_README.html#recipient
I agree with this. The problem is that your machine is accepting the mail. > The second step isn't required, but will reduce load on your > system. Convince them (use a creative explanation about > system security) to log in as root and run this one-line patch > to their system: > postconf -e unknown_local_recipient_reject_code=550 Maybe they can be convinced that this presents no loss of mail. Postfix 2.4 and later no longer reply with 450 for non-existent local recipients. Wietse