Originally posted HERE [http://bradthemad.org/tech/notes/exim_cheatsheet.php]
Message-IDs and spool files
The message-IDs that Exim uses to refer to messages in its queue are mixed-case
alpha-numeric, and take the form of: XXXXXX-YYYYYY-ZZ. Most commands related to
managing the queue and logging use these message-ids.
There are