1. Sign into Dynamics 365 (online) as a user with the following privileges:
- Global Administrator or Exchange Administrator role in Office 365
- System Administrator role in Dynamics 365
2. Navigate to Settings and then click Email Configuration.
3. Click Mailboxes.
4. Change the view from my My Active Mailboxes to Active Mailboxes.
5. Select the mailbox and then click the Approve Email button.
6. After the mailbox is approved, you can select the mailbox and then click the Test & Enable Mailboxes button.
NOTE: If the test results are something other than success, you can open the mailbox record and click the Alerts section. View the details of any errors that were logged.