Yes, you can. Since permissions for Private Messaging are granted by you on a Guest-by-Guest basis they need to be turned off on a Guest-by-Guest basis as well.

To turn off the Private Messaging feature for a specific Guest, follow these steps:

1. Click on the Settings icon in the OPTIMAL toolbar.
2. On the Guest Accounts tab

3. Locate the Guest you want to disable messaging for and click on ther account number in the Account column.
4. Set the Messages drop down to No Access.
5. Click the Save or Modify Account button.

The PMC is now disabled for this Guest. They will not be able to leave messages for you, nor will they be able to access the Message Center to view messages.