This is only needed in case of bounces generated by locally emitted
messages. We neither store these, nor do we create mail boxes on a
firewall. Safe to drop.
Cc: Michael Tremer <michael.tremer@ipfire.org>
Signed-off-by: Peter Müller <peter.mueller@ipfire.org>
Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>