Block an email address or Active Directory group
- In the administration console, in the left pane, click Blocked users.
- Click
.
- Do any of the following:
- To block an email address: In the Users field, type the full email address of the user that you want to block.
- To block a Microsoft Active Directory group: In the Active Directories field, type the name of the Active Directory group that you want to block.
- Click Save.