Works well, needs a bit of work though

Works well, this script checks the mailqueue by directly counting the files in the queue directories, which has the advantage that is will probably be much faster for queues contains 1000s of mails.

Two minor things (not sure if this is right place to report bugs), the command parsing calls the script itself which doesn’t make any sense if a parameter is ignored and the check reports 0 for all queues if the directories are not readable due to incorrect permissions or user, in this case /var/spool/postfix is usually readable, but the queue subdirs are not.

A revised script is available here: https://gist.github.com/alexlehm/8084195