Ahh, ok, now i got it. I thought, a similar question was already answered but it seems I missed the answer on my own question, sorry. It stayed in my outgoing box an I assumed, there was a delivery problem. That's why I sent it twice.
Back to the problem, as I pointed out, the delivery attempts to the other postfix system from my server started to fail after hitting the hard error limit so it refused to accept any further message on this connection. It seems either the other server did not close the connection or my server did nod recognize the connection end, since my server tried to send mail across the old connection. After I disabled the connection cache, sending mails worked as supposed. They got greylisted first and could be delivered at the second attempt. Due to earlier problems with this particular server i configured my server in a way, that it splits a mail with multiple recipients in separate mails btw. I think, that postfix as a server should close the connection after its hard error limit is hit, since it won't accept any mails on this connection anyway. And, on the other side, postfix as a client should not reuse a dead connection. Yours, --Thomas Am 24.02.2017 um 12:31 schrieb Alex JOST: > Am 24.02.2017 um 09:03 schrieb Thomas Minor: >> Hmm, ok, >> >> I did search but found nothing. I'll check again. > > http://marc.info/?t=148763167000002&r=1&w=2 > -- Thomas Minor, Development H & R Netzwerk GmbH Am Königsweg 9 48599 Gronau-Epe Sitz: Gronau / Westf. Handelsregister: Amtsgericht Coesfeld, HRB 5886 Geschäftsführer: Harald Beine --
