I'm hoping someone can help me figure this out or possible point me to a post that may have already solved this issue.
We are currently finalizing our migration from 2007 Exchange to 2013 Exchange. All our normal users are moved over to the 2013 Exchange. We are moving from a single server to multiple servers. Our current configuration is this:
Exchange 2007 server (current roles - Mailbox, Client Access, Unified Messaging, Hub Transport)
Exchange 2013 server B (current role - Client Access)
Exchange 2013 server C (current role - Client Access)
Exchange 2013 server D (Mailbox)
Exchange 2013 server E (Mailbox)
What is happening is that certain emails going to certain users are not making it to them, I would say 95 -98% of the emails are making it to the users with no issues. From what I'm seeing in message tracking is that any that go to the old 2007 server are not being sent to the onto the proper 2013 server that has the that users mailbox. What I'm trying to figure out is what can I do to resolve this. Any suggestions would be much appreciated.