After the DNS domain that you were coexisting with has been moved, the ODM Domain Coexistence feature should no longer be necessary.
The following steps will turn off Domain Coexistence (address rewriting) and remove the connectors from your tenants.
1. Turn off address rewrite for the individual users
- In the ODM Portal | Mailboxes tab, select the filter "Address Rewrite: On"
- Select all
- Click the "@ ADDRESS REWRITE" button
- Stop address rewriting for the selected mailboxes
2. Disable the Domain Coexistence service
- In the ODM Portal | Migration (left-pane) | Accounts | Dashboard, find the Domain Coexistence pane and click Disable:
3. Delete the Quest Coexistence Rules
- Open the Office 365 Admin Center
- Open the Exchange Admin Center
- Click Mail flow
- Click Rules
- There should be two "Quest Coexistence Rules" defined, these can be deleted within the rules.
- These two rules will exist in either the source or target tenant.
To Source: The rules will be located in the target
To Target: The rules will be located in the source.
4. Delete the Quest Coexistence Connectors (Applies to both source and target tenants)
- Open the Office 365 Admin Center
- Open the Exchange Admin Center
- Click Mail flow
- Click Connectors
- Delete all "Quest Coexistence Connector *" connectors
5. Delete the Quest Coexistence Group
- Open the Office 365 Admin Center
- Open the Exchange Admin Center
- Click Groups
- Select the Mail-enabled security tab
- Delete the Quest On Demand Coexistence group
To Source: The group will be located in the target
To Target: The group will be located in the source.
Note: These steps are in order to least to greatest impact. Allowing some amount of between each step to ensure that there are no unexpected mail flow issues.