On 02/12/2021 17:53, Maarten Oelering via mailop wrote:
Hi,
Sending 400K mailings with Exim, hats off! With large mailings you
will always see some messages failing due to various reasons. Even
with more powerful MTAs. I would expect that the 1000 mails are left
in the queue due to the to 454 … over quota replies from Gmail. Are
they all connection errors? Then I would suspect a problem on your
side. An SMTP trace could help to diagnose the issue.
Oh...... WHOOOOPS! I meant 400Kb in size! :-)
Most of them are still queued and not (yet) sent. As this has been
happening for a couple of months, I expect the emails will eventually
get accepted but after a couple of days of trying.
They timeout after DATA.
These are legitimate emails, invoices, call recording etc.
Things we have tried (which haven't helped much):
Made retry more aggressive for Gmail servers (made a slight improvement)
Increased data timeout in SMTP sessions
Tried reducing MTU (can't pmtu discover to gmail as they block too much
ICMP) - no difference
ping/mtr - no packet loss
Checked IPv4 vs IPv6 - no difference
Ran Exim under full debug - it's hanging in the TLS traffic. Seems to be
after DATA.
Ran Exim without TLS (accidentally) - didn't make a difference, so TLS
is likely a red herring.
Andrew
Maarten, Postmastery
On 2 Dec 2021, at 13:50, Andrew Hearn via mailop
<[email protected]> wrote:
Hello,
We're a UK ISP, and relay email for our customers as well as send
our customers emails such as invoices.
We currently have about 1,000 emails queued for google accounts and
these are failing with a timeout, eg from exim:
2021-12-02 11:48:05 1msize-005feQ-DI H=gmail-smtp-in.l.google.com
[142.250.13.26] TLS error on connection (send): The TLS connection
was non-properly terminated.
2021-12-02 11:48:05 1msize-005feQ-DI H=gmail-smtp-in.l.google.com
[142.250.13.26]: SMTP timeout after sending data block (525043
bytes written): Connection timed out
Based on past experience, eventually, the emails may will through.
This is also intermittent, as sending to my own gmail address tends
to get through eventually, though they do still time out once or
twice before eventually getting through.
Generally these emails do show as SPF/DKIM/DMARC PASS in gmail.
This report is rather vague, but we do have further examples, logs,
pcaps.
Is someone from google on this list able to help investigate this
problem with us please? I can pass examples and pcaps privately.
Thanks!
Andrew, AS20712 aa.net.uk
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