Custom Email Options can be set to prevent users from replying to notifications for each group.
To get to Custom Email Options, navigate to the Group Settings page. From the group page, go to Settings.
Scroll down and expand CUSTOM EMAIL OPTIONS
Select the appropriate reply to options.
Do-not-reply can be set as the from name and from email address in order to indicate to recipients not to reply to the email. For example, email@example.com
Another option is to choose Member Select who replies are sent to to prevent replies from coming back to the author of the message and to leave the address line blank.
Make sure you check the box to use the custom settings you decide on!