To send messages to the whole contact group, press the right mouse button on the group name and choose “Send a message to a group” in the context menu (Picture 1).

Picture 1

In an open window (Picture 2) you can see:

– contact list in a chosen group (1),
– delete button of a chosen contact from the list (2),
– text box for sending out (3),
– send button to chosen contacts (4).

Picture 2