On my current/macppc, trying to remove message from the queue kills the whole smtpd:
# mailq MTA|d4c2da0cc94048ad|ENQUEUED|r...@mini.stare.cz|jan.st...@fjfi.cvut.cz|1339601616|345600|3|450 4.1.8 <r...@mini.stare.cz>: Sender address rejected: Domain not found # smtpctl remove d4c2da0cc94048ad command succeeded But in fact, this is what happened: Jun 13 17:34:40 mini smtpd[27289]: queue handler exiting Jun 13 17:34:40 mini smtpd[15931]: lost child: runner terminated; signal 11 Jun 13 17:34:40 mini smtpd[8176]: mail filter exiting Jun 13 17:34:40 mini smtpd[31784]: smtp server exiting Jun 13 17:34:40 mini smtpd[19697]: lookup agent exiting Jun 13 17:34:40 mini smtpd[9160]: mail transfer agent exiting Jun 13 17:34:40 mini smtpd[32734]: mail delivery agent exiting Jun 13 17:34:40 mini smtpd[21481]: control process exiting Jun 13 17:34:40 mini smtpd[15931]: parent terminating and the message is still there: # mailq MTA|d4c2da0cc94048ad|ENQUEUED|r...@mini.stare.cz|jan.st...@fjfi.cvut.cz|1339601616|345600|3|450 4.1.8 <r...@mini.stare.cz>: Sender address rejected: Domain not found Jan