I've read several posts on similar issues but this one is slightly different. I have a user (not a new user) whose mailbox doesn't show up in the GAL. The user has always had an AD/Exchange account but he was also on a Lotus/Domino system as his primary email. I created an Exchange contact for his Lotus/Domino address and had his AD/Exchange account forward to his Exchange contact in Delivery Options on the Exchange General tab. I also hid his AD/Exchange mailbox from the GAL on the Exchange Advanced tab.
The Lotus/Domino system and Exchange were never connected, i.e., no special connectors set up in Exchange or Lotus/Domino.
When he no longer needed Lotus/Domino, I deleted his Exchange contact and un-hid his AD/Exchange account from the GAL. However, after a few weeks he still does not show up in the GAL. I haven't done anything with RUS because my assumption is it's a different issue although I'm not ruling out RUS. New accounts created seem to show up in the GAL with no problem. You can send him email by typing his email address and messages sent to groups he is a member of reach his inbox as well.
Any suggestions are greatly appreciated.