On July 13, 2018 12:11:13 PM PDT, Eric Abrahamsen <eric@ericabrahamsen.net> wrote:
All messages are correctly archived in hyperkitty. smtp.log always shows "for 5 recips", even for the messages that the two users aren't getting. These two users only ever miss messages sent by the other.
....
Is there any way to get a better sense of where things are going wrong? Turn up the logging verbosity? Send test messages? Get more diagnostics?
Mailman has delivered the messages to the outgoing MTA and can't tell you any more. Mailman 3 bounce processing is broken.
Look in the MTA logs for more.
One possible issue is DMARC, but if you aren't applying DMARC mitigations, that should affect all messages from the Yahoo user to the Gmail user.
-- Mark Sapiro <mark@msapiro.net> Sent from my Not_an_iThing with standards compliant, open source software.