Thank you for your prompt response Mark,
Στις 2019-09-18 19:12, Mark Sapiro έγραψε:
Is only one list affected, and is it all messages from this list or only some?
Just two messages from this certain list. Subsequent messages and other activity seems to work properly
Do some deliveries of the problem message succeed?
I think not, the IndividualDelivery lines list all all recipients (list is small so I was able to check)
Postfix can return a 421 status and drop the connection if there are too many invalid local recipients, although I don't know if this would apply in the VERP case.
Well there is no connection to postfix at all when the runner starts and the "Cannot connect to SMTP server" log shows up. Otherwise I'd have seen something in the postfix logs or tcpdumps in localhost.