Hi list,
sorry for my belated reply.
First of all: thanks for the input to everyone suggesting where / what the
error may be.
What I tried so far:
1) reducing the MTU all the way down to 1400 - no change, error still persists.
I will now proceed troubleshooting by sniffing the network communication, maybe
I am able to gather clues doing so...
-----Ursprüngliche Nachricht-----
Von: owner-postfix-us...@postfix.org [mailto:owner-postfix-us...@postfix.org]
Im Auftrag von Wietse Venema
Gesendet: Montag, 27. November 2017 21:39
An: Postfix users <postfix-users@postfix.org>
Betreff: [MASSMAIL]Re: Duplicate mails in mailq / always_bcc
Niclas Rautenhaus:
> 5086760443 35318 Mon Nov 13 16:04:20
> u...@externaldomain.tld<mailto:u...@externaldomain.tld>
> (lost connection with 192.168.N.NN[192.168.N.NN] while sending end of
> data -- message may be sent more than once)
This is the result of Postfix reading EOF, not a Postfix timeout (that produces
a different error message).
Postfix may read EOF as the result of some other error at a lower layer in the
network stack.
A more precise determination would require a network sniffer. Just the packet
metadata (no data content) might be sufficient.
Wietse
