I have over 260,000 emails in my mail queue

There could be a number of problems. Spammer on your box, someone misconfiguring their email settings or a bad configuration in your exim setup.

You need to look at who they are to, if they are on or off server, and you need to look AT the message to see where they are coming from.

Also look at the view relayers to see if someone is spamming from your server.

 

Do you have a cPanel demo account on the server?

 

Boy i'd hate to be on that server.....

 

I kinda let the thread hang for similar reasons.

Abe- I suggest you think about employing one of the many fine server administration companies that frequent around here. There are simply too many possibilities to try and run through them all in a post. Someone really should take a look at what is going on so a sane fix can be suggested.