I was working on getting some Exchange log information today and came across something that I thought was strange. First let me give you some background on our setup. We have 3 Mailbox servers and 3 CAS servers. All of which are in a DAG. Two of the mailbox servers and 2 of the CAS servers are located here in our data center. We have a mailbox and CAS server in another data center. The majority of the time all of our mailbox databases are mounted in our local data center. In AD Sites and Services The remote Exchange server has an IP address that is associated with a network that is under the remote data center site.
So looking through some of the logs I noticed that when users were sending email internally, the email would go out to the remote mailbox server and then route to the mailbox server that is located here. Again all of the mailbox databases are mounted on the servers here. I am not sure why this is happening or how to change it. But basically if a user whose mailbox is on database "A" on Server 1 sends an email to another user in the same database, the email goes to server 3 and then routes back to Server 1. Why is this happening? How do I fix it.
Thanks,
TD