Support Reps have same signature which is NOT theirs

Here's the problem and tech support has been no help. We have 4 support reps in our system. When a support rep replies to a request using the web application the default signature is getting pulled from SOMEWHERE, but is not a support reps, its a user who was pulled in from active directory who was NEVER a support rep.

The technical support I received just said to go to personalize for the admin account and set the signature, sorry but that didn't work. First off the signature we see wasn't even there. Second, setting a new signature didn't override the one that already appears.

Can anyone tell me WHERE in MySQL the signature is stored? If I can get this information I can at least alter or delete the one that is coming up.