Call it a blast email, mass email, or group email, how do you send one?
It's really quite easy.
Select the group:
Click on the chevrons to display them on the right:
Use the Check boxes to select who you want to send the emails to:
Then click on the email icon and pick your email!
IMPORTANT NOTE: Clicking on BCC means you will get a BCC copy for ALL of the emails that you are sending here.