I have a very strange issue with Exchange 2007 and I need some help. We are always fighting SPAM and malicious emails, and most issues with them are straight forward. However, we have been getting emails to a non-existent user, gsewsrsr, and then it is forwarded to a brand new user jdoe. I see the email come through the barracuda, to email@example.com, get "Allowed" and then forwarded to the inbox of firstname.lastname@example.org. I have checked throughout exchange and there is no reference to gsewsrsr anywhere in distro lists, mailboxes, alias, ect. I am worried this is some sort of Exchange infection, as I cannot figure out why (A) the email to gsewsrsr is being accepted by our domain and (B) why it is being forwarded to jdoe (who by the way is a brand new user).
Exchange version is 2007 SP3, running on Server 2003 R2 64-bit.