I'm running Mailman under Docker (maxking). I've a test list with a max_message_size set to 0 (unlimited). I know it's not what anyone should be doing in production, but I still want to test this. I've sent a series of messages with increasingly larger attachments to the list. Going up in 5MB increments, I find that while a message with a 15MB attachement gets through to the list members, a 20MB one doesn't.
The interesting thing is the message in the mail logs:
Jun 19 11:44:50 venus postfix/lmtp[17630]: C0C7928564: to=<mj@lists.scss.tcd.ie>, relay=172.19.199.2[172.19.199.2]:8024, delay=109, delays=2.2/0.04/0.01/107, dsn=5.0.0, status=bounced (host 172.19.199.2[172.19.199.2] said: 552 Error: Too much mail data (in reply to end of DATA command))
So 172.19.199.2 is complaining about "Too much mail data". That's the IP address of the mailman-core container. I'm wondering why this is happening, and where the decision is being made, as it seems at odds with the fact that the mailing list has no limit on message size.
Would be grateful for any insights, many thanks. Stephen Kenny