Mail gets forwarded from user1@domain1 to me@domain2
But there is no alias defined for user1@domain1
How do I go on to debug and find this?
I want to forward this mail to a couple of other users, bur the “hidden” alias overrides this.
It was configured at some point.
Perhaps it’s a BCC map, a filter in the filter tab in /mailbox, a user defined sieve filter, a catch-all alias?
Dovecot and Postfix logs from the time of the forwarding will help to solve this.