I have a mobile user that has a laptop using RPC/Outlook 2007 and a BlackBerry.
About a week ago whenever he would reply to a certain user from another company he would get a NDR message.
I have researched this with him a bit and it turns out whenever he replies to this user via Outlook or his BlackBerry he gets a NDR.
Now... he can inititate a email to this user and it goes through fine, this has got me stumped, any ideas?
He is having NO other problems with emailing other people at all...
The recipient he is sending to is on a Exchange 2007 server if that matters...