Exchange User Cannot Email A Remade Account

Staff member left and came back to the company so the email was deprovisioned and reactivated.  When users aren't able to email him we delete any cached email entries and out of the 50 or so users that had an issue, only 1 has not been resolved.  This particular user gets a bounce back email stating:

Everything in italics has been edited by me.  Any idea on how to fix this?  I read a number of articles and tried to enter a x500 entry but that didn't seem to work.  (I may not have added it correctly)

Thanks!

Bobby