I deleted a user mailbox at the direction of MS to fix the mail stuck in the outbox problem. This inadvertently deleted the user record. I restored the user record using adrestore and created a new mailbox for that user. Now the user receives mail from everything except other internal outlook clients (2003 and 2007). The sender gets a recipeint not found in e-mail system undeliverable message. I thought it might be an offline address book problem but it does seem to be up to date as it has recently added users. The exchange server is 2007 sp3. As always any help is appreciated.

To rule out the offline address book issue try using OWA. I suspect, however, that this is an autocomplete (nickname cache) issue on the sending user's Outlook (using OWA will also bypass this).Lanwench ** Do not fold, spindle or mutilate. Fill in the box completely and erase any stray marks. Use only a #2 pencil.

I also had to download the offline address book on outlook 2003 clients.