Exim queue full of spam.
When you do have the exim queue on the server full of spam, so full that you cannot even open the WHM email queue or the CSF email page because it takes ages, here is a very handy script that will help you deleting the exim queue selectively, from the same SSH command line. That is, you can delete only that long list of messages of the user spamming without affecting the good users emails:
DelExim script
Obviously use with care. Deleting things is always a non reversible process, so if you are too strict and you put a regex string too wide it may delete good stuff. Try to be very specific at the beginning and do it in several passes. You can run the script as many times as neeced, so first you can try ‘nobody@<server name>’, then the ‘@<account spamming name>’ and so on. But as soon as you can open the email queue it is good to finish the job with WHM email queue or even better, CMQ (ConfigServer Mail Queue) an addon to WHM that is really handy when having to deal with large lists of emails to refine them