You can send an email to members of a group by accessing the Actions section of the My Groups homepage.
To use actions, follow these steps:
Click the Groups tab on the left navigation bar.
Click on the Homepage icon. The Group homepage appears.
Below the Actions label is the E-mail Group button. Click on this button to open the compose window in the My Email area.
The email is addressed to all members of the group.
Compose a message and click on the Send button to send a message to all group members.