We currently have 3 Exchange servers on an MPLS network.
All email comes into the NY server, and is routed through a Smart Host on the DC server (required for TLS encryption mandated by a couple of our clients). Each physical server has it's own routing group and routing group connector.
So, if I mail comes in for a user with a mailbox stored on NY server, the MX record points to NY server, the NY server then sends the mail to a smart host on the DC server, after which, the mail is sent back to the NY server for delivery to the users mail box. This works fine, and is only necessary due to some clients requiring TLS encryption for both sending and receiving mails.
The problem arises that our DC office will be having a scheduled power outtage over the weekend. Therefore, even if a mail was destined for delivery in NY, it will not be sent to the NY mailbox, but will instead be queued until the DC server comes back up.
Can someone recommend a full mesh scenario where such service interruptions like the DC server going down, would still facilitate mail delivery to other offices?