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. Click to open Advanced Settings
3. Navigate to Settings and then click Email Configuration.
4. Click Mailboxes.
5. Search for the mailbox you want to approve.
6. Select the mailbox and then click the Approve Email button.
7. After the mailbox is approved, you can select the mailbox and then click the Test & Enable Mailboxes button.