This e-mail message cannot be delivered to Email because the email-address is no longer valid
Posted on 2014-04-17
We have recently replaced a Windows 2008 SBS (Exchange 2007) with a new server Windows 2012 (Exchange 2013).
All users are experiencing problems when they attempt to reply to [internal] emails submitted prior to the migration.
This e-mail message cannot be delivered to %Email% because the e-mail address is no longer valid.
This is creating major havoc. Any assistance would be greatly appreciated.