MicrosoftBhavesh Shah Would be interested if you found a solution for your question. Had a talk with a MS consultant and with partner tech support. We have a support statement from MS for use of Exchange Server 2016 server as management server only. This means Exchange Server is not included in mail routing and all mailboxes are hosted in Exchange Online. In my current setup hybrid wizard is not used. The sync of Exchange attributes with AD Connect is activated. Only use of Exchange Server is to manage the Exchange attributes in AD.
At the moment I try to work with the Management role only. The system is configured with 4 cores and 8 GB RAM but it seems this can be reduced to 2 cores and 4 GB RAM. But I have not finished testing the setup without mailbox role.
