The mail remains in the var/spool/QUEUE directory for quite some time and the qf*-files have information like:
M Failed to resolve domain example.com
I would like to have this hard bouncing, so I have added
^Failed to resolve domain
to conf/bav/bav.rule's [hard]-section.
After restarting OpenEMM the qf*-files get refreshed, but the mail is not hard bounced.
What have I to do in order to get bouncing running with Mailgun?