I've been getting a few errors lately where user Id provided by the email is not one of our users. If I put the user ID into the URL, I get an "Insufficient Privileges" error. As I'm the admin, I'm assuming that this user actually relates to some sort of automated process. Is there any way of knowing who/what that Id is or identifying the process?

The issue itself that was causing this error can be fixed, so I'm not too worried about that. However, it would be good to know how to identify this mysterious user/process.

Thanks,