Help with 'The message has no valid senders'
by McGuire, Tommy M. (MSFC-IS90)[EAST2]
We recently installed Mailman 3 to replace an existing Mailman 2 installation with a large number of lists and users. I'm now seeing a number of users on specific lists whose posts result in:
May 18 14:25:41 2021 (112570) DISCARD: <BY5PR09MB52987327DE1AA2C199DC4DC1D42C9(a)BY5PR09MB5298.example.org>; ['The message has no valid senders']
The post have sender addresses, which are members or owners of the lists, and as far as I can tell, the users are valid. Can anyone shed any light on why a post wouldn't have a valid sender?
Tommy M. McGuire