Within the Groups module, you are able to send emails to group members. This way you would be able to communicate with all group members easily .
How to email group members
Click Groups or the People icon on the left menu.
Click on the View button on the group you would like to send an email to.
Click the Emails tab at the top of the page.
Here you will see a list of past emails that had been sent out to the group. Click the New Email button to create a new email.
Create the email and send it to the group members.