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.
