Hello,
So i´m moving some users to office 365 from SBS2011. After moving a single user and making the connections between office365 and Exchange all mailflow is working but I get an NDR with IMCEAEX- when replying internally (another user within Exchange) to an old email from the user or selecting the user from the Outlook address cache. I cant have all the users delete ithe cache or have them change the address when replying to old messages, so I need a way to route those messages to the external contact I´ve created or to the new server.
I keep reading that you have to assign an X500 address to the old user, and the value of legacyexchangedn but dont know exactly where I´m supposed to assign it, the mailbox doesnt exist anymore on Exchange (the user account does). Do I assign it to the external contact I´ve created within the Exchange org? Please help.