On Wed, Sep 10, 2014 at 09:56:48AM +0200, Sean Durkin wrote:
> Some of my users were complaining about losing incoming mail,
> namely Amazon shipping notifications, newsletters and such things
> that they were absolutely sure were sent out, but never reached
> their inbox. After doing some digging, increasing log verbosity
> and such, I found a lot of this:
Have you tried disabling TCP window scaling? It might be confusing
some middle-box (firewall, NAT device, ...) on path between the
remote systems and your MTA.
> [... snip ...]
> Sep 10 00:06:37 mail postfix/smtpd[23095]: lost connection after DATA (17511
> bytes) from smtp-out-127-108.amazon.com[176.32.127.108]
Post the hostname/IP address of the receving system.
Capture and examine a tcpdump recording of mail from one of the
problem senders. Any sign of retransmission by the sender?
For at least one such session, post all related messages from the
"postfix/smtpd[pid]" that occur between "connect from" and
"disconnect from".
--
Viktor.
