I setup BCC for one domain to send copies to a mail archive. Incoming mails where not send to the archive. Outgoing mails works.
relayhost <-> mallow -> archive server
Sender based transport map has a rule to send trough a mail relay for this domain
Transport-Maps has a rule for the archive mail address and the archive server as next hop
At BCC-Maps I added two entries. One with BCC-Typ sender and one receiver. Local target ist @MYDOMAIN and BCC-Target is the mail archive address.
In postfix logs I see outgoing mails become the BCC address and where send to the mail archive server. For incoming mails nothing happens.
Also I setup the relay host under the relay hosts to disable spam filter because spam filtering is done by the relay host.
I read something about BCC headers were set with postfix earlier but now its done in rspamd. So it could be the problem that the relay host has spam filter disabled? If this is the problem exists any workaround for this?