exim_paniclog
Here's an interesting thing that's recently showing up in exim_paniclog:2003-07-20 08:19:10 19e8ma-0004Bm-Ql User 0 set for local_delivery transport is on the never_users list
It's got something to do with root and mail being sent from it, I believe.
Note: I've got the new & somewhat improved CPanel7.