We've migrated many of our users using Exmerge and now when they reply to a message it gives looks like it is going to work but fails with an undeliverable message. If you click on the username in the "To..." field it is blank in SMTP and fails. If they create a new email it works just fine and they can send no problem. It appears that the Distinguished name of of the old emails contacts (To.., From..., etc) are still referencing the old forest and therefore when the user is trying to reply to these old emails it is 'looking' in the wrong forest, hence the undeliverable. We've looked at TONS of articles regarding migration with Exmerge and never even heard of this, is this a failure of Exmerge, how it works normally or something we are doing wrong? Thanks!