Mailbox migrations from Exchange 2010 to Exchange 2013.
Recently a batch of user migrations were created only to find some of them failing. The error is as follows:
“Error: MigrationRecipientNotFoundException: A recipient wasn’t found for “firstname.lastname@example.org” on the target. Create a recipient of the appropriate type for this migration on the target and try again.”
First thing to check is if the mailbox exists!. “We added the batch so it should exist” is the response. Upon investigation, the user account in AD was disabled and subsequently the mailbox was disconnected hence the error.
Hope it helps.