MailQueueCleaner Failure Report On Ensim Server

I got a RHEL dedicated server it has Ensim Ensim Pro 4.0.3-22.rhel.3ES

I got a few email accounts over quota limit. Even though it reached the quota the still consumes mail.

the size keeps increasing until HD space runs out.
I checked other forums and they recommended to

do this
find /home/virtual/site#/fst/var/spool/mqueue/ -exec rm -f {} ;

I did this but there were no files in there to begin with.

So every hour i keep getting this failure notice.
This is a report generated by the hourly run of MailQueueCleaner. Some sites on this server have problems which prevent the processing of their email queues. UNTIL YOU RESOLVE THE PROBLEMS, THESE SITES WILL NOT BE ABLE TO RECEIVE EMAIL. A summary of the problems is included below.

sites over the quota show up here.

I just want to be abl to clear the mail out of selected accounts without logging in the account. I am sure it is some file to clear.