We will be migrating our on-prem Domino messaging environment to Exchange On-line in our Microsoft 365 tenant. Currently we have 2 C300Vs in the DMZ acting as our edge SMTP servers. Currently, outbound traffic is routed to the Internet. On the weekend we cut-over to Exchange Online, we need to route this traffic to our M365 tenant.
I was not with the company when these appliances were configured. There is limited internal documentation. I can't seem to determine where this change should be made.
Any and all assistance would be greatly appreciated.