We have two Exchange 2010 servers set up in a DAG configuration; Exchange2 and Exchange3 and replication is happening correctly. However, this morning I saw email messages from Outlook indicating that delayed messages existed. Upon further examination, I see that email that normally flows out of the organization via Exchange2 has actually sent the mail to Exchange3 and it sits in that queue. No configuration changes were made recently so what would cause my mail to flow to my alternate server vs. outbound to the Internet?
If so, this is by design, so that emails are not lost if one server goes down.