Forum Discussion
How to decommission on-premises exchange servers and move completely to O365
Thanks Peter and Nuno.
Based on this I am thinking of following revised plan:-
1. Set up a connector in O365 to Mimemcast with "*" as the recipient domains and disabling the "Outbound to OnPremisesServerGUID" connector.
And then running the Hybrid configuration wizard to remove the centralised mail flow setting.
This should make the email flow from O365 directly to mimecast instead of going through on premises server.
I need to ensure that O365 spf is included in our spf (for all our domains).
2. Leave current exchange server that relays mail on-premises. Does that only need the CAS role (exchange 2013)?
3. Change Mimecast to route mail to OurO365TenantName.mail.onmicrosoft.com rather then our on-premises servers.
4. Remove following connector from on-premises server to make it route mail through O365:
Identity AddressSpaces Enabled
-------- ------------- -------
Exchange On-Premise to Mimecast {SMTP:*;50} True
Do you see any problems with this plan.
The plan sounds good yes. Only other suggestion I would have is to install a new Exchange 2016 Server to be the hybrid management server. If you have O365 Enterprise licences in your tenant you will be eligible for a free Exchange 2016 hybrid licence key (on the condition that no mailboxes are hosted on that server). Running the HCW on the new Exchange 2016 server will detect this eligibility when you sign in to O365 and assign the licence.
Not an essential step, but it gives you the current supported hybrid configuration. Once you have the Exchange 2016 server installed, you can move the arbitration and discovery management mailboxes etc over to it, and create a connector for SMTP relay. Then you will be free to decommission the older Exchange Servers (assuming you have no remaining on-premises mailboxes of course).
Thanks Peter and Nuno.
thanks ...we might move the internal apps to O365 smtp relay to allow redundancy (as a single exchange server will not have redundancy)
But keep 1 server for mailbox management purposes.
Also, does this single exchange server (that we need to keep on-prem) need to have the CAS and mailbox server roles....or we can install the console only on this server for mailbox mgmt purposes only?
I am trying to see if MTA can be removed from the one server that needs to be left there.Hi curious7,
As PeterRising said, you will need to install the mailbox role to have a full exchange installed and supported.
Best Regards,
Nuno Árias SilvaYou will need to install the mailbox role. You can't install Exchange 2016 without it. Exchange 2016 consolidates roles from previous versions into only two roles which are Mailbox and Edge Transport.
At the moment we will be keeping 1 exchange 2013 server (may upgrade later to 2016 and license it using HCW as per your advise). So I guess I will need both CAS and mailbox roles on it?
So is there no way to get rid of MTA on it?
