Speaking about MTA specific behavior: `exim4 -bpc` simply prints the number of messages in the queue, and is *much* more efficient than printing the message details by `mailq` (which is `exim4 -bp`) for just counting them. This can make a difference between a timeout and proper report when you have thousands of messages in the queue.
-- Reply to this email on GitHub: https://github.com/monitoring-plugins/monitoring-plugins/pull/1208#issuecomment-49587389
