Apologies if this question has been answered before. We are going for Exchange hybrid migration to Exchange Online. On-premise, we have Exchange 2016 mailbox and Exchange 2016 Edge transport servers, DLP appliance (Forcepoint 8.4) and Cisco Email Security as our mail gateway.
We are enabling Centralised Mail Transport (CMT) because we wish to retain the DLP appliance for now until all mailboxes are migrated.
1) When running the HCW, should I choose the Edge Transport server as the Optimal server or the Exchange 2016 mailbox server? The Edge Transport server is used for address-rewrite for outgoing emails. Incoming emails do not traverse the Edge Transport server.
2) Is there any additional configuration needed on the send/receive connectors, so that email delivered to the online mailbox is routed back to the on-premise Exchange (CMT) without issues. I read somewhere that you should not have any device or systems in between the on-premise Exchange and EOL that modifies the email.
3) Is there any address rewriting capabilities in Exchange Online?
4) Please advise if having Trend Micro IMVSA and ForcePoint in between on-premise Exchange and Exchange Online would cause any problems?