To send instant messages with Messenger, review message history, or manage contacts, you must have Messenger running with the window open or with it minimized in the notification area of the Windows taskbar.
Note: Opening Messenger requires the "Secure Messenger, Open" security right.
To open Messenger
In Office Manager, do one of the following:
Click the Secure Messenger button 
on the toolbar.
On the File menu, click Secure Messenger.
The Messenger window opens.
If you minimize the window, you will continue to receive messages.
To maximize the window after minimizing it, do one of the following:
In Office Manager, click the Secure Messenger button on the toolbar.
In Office Manager, on the File menu, click Secure Messenger.
Double-click the Secure Messenger icon 
in the notification area of the Windows taskbar.
Right-click the Secure Messenger icon in the notification area of the Windows taskbar, and then click Maximize.