> There is no mails in queue, which fail to delivered. Messages to already > known/verified addreses delivered normal to backend servers. > > But verify often fails with error "Recipient address rejected: unverified > address: lost connection with mail.xxx[x.x.x.x] while receiving the > initial server greeting."
PLEASE DO NOT SHOOT THE MESSENGER OF THE BAD NEWS. Address verification uses the same SMTP connections as normal email (unless you changed this with address_verify_transport_maps etc.). When your downstream servers can't handle new connections, then you need to reduce the number of PARALLEL connections to the downstream servers until the errors stop. http://www.postfix.org/postconf.5.html#transport_destination_concurrency_limit Use "postfix reload" when you change concurrency parameter settings. When your downstream servers are really bad, then you will also have to insert delays between email deliveries. http://www.postfix.org/postconf.5.html#transport_destination_rate_delay Use "postfix reload" when you change rate delay parameter settings. If you still have connection failures with _destination_rate_delay then the downstream servers need to be replaced. Wietse
