NOTE: You will not see this option if you are not associated with any Groups.
Sign in to your account.
From the upper right-hand corner, click the envelope icon.
Click New Message > Send a Message.
Select a "Group" to message.
Select either "All" or "Selected."
All: Message will be sent to everyone in Group.
Selected: You choose who you want to send the message to.
If "All" was chosen...
Update the "Editor."
Plain text: Very simplistic text style. Looks like a text message.
Rich text: Can change the font, font size, bold, italics, underline, etc.
Input a subject line and body of the message.
Click Send Message.
If "Selected" was chosen...
Search for the group members that you want to send the message to.
Click Select Members.
Update the "Editor."
Plain text: Very simplistic text style. Looks like a text message.
Rich text: Can change the font, font size, bold, italics, underline, etc.
Input a subject line and body of the message.
Click Send Message.