Decommissioning On-Premise Exchange Servers in Hybrid Environment
1. Assuming successful migration of the mailboxes to the Exchange online, the user can point the MX and Autodiscover DNS records to Exchange Online, instead of on-premises.
2. Remove Service Connection Point (SCP) values on your Exchange servers. It ensures that no SCPs are returned and client will be using DNS method for Autodiscover.
3. Now, it is required to delete the inbound and outbound connectors created by Hybrid Configuration Wizard. To do this log on to Office 365 admin portal and sign in as Tenant Administrator.
4. Select the option to manage Exchange.
5. Navigate to Mail Flow->Connection.
6. Now, delete the inbound outbound connectors.
7. To remove the organization relationship created y the Hybrid Configuration Wizard, log-in to Office 365 Admin Portal and sign in as Tenant Administrator.
8. Select the option to manage Exchange.
9. Navigate Organization-> Organization Sharing->Remove the organization named O365 to On-Premises-<unique identifier>.
10. Now, uninstall the Exchange from on-premises server.