It is fairly easy to delete email messages that get frozen in the EXIM queue.
Frozen emails enter the queue usually when you're trying to send a bounce message in response to spam that got delivered from a non-existing email address.
Exim often keeps retrying - depending on the mail server configuration and this can end up with a lot of storage and cpu cycles going to waste.
An easy way to delete them is through a cron job that does the following:
Code:
exiqgrep -z -i | xargs exim -Mrm
Delete Frozen EXIM messages 
