You can turn on message moderation to approve or block messages before they’re sent to the rest of the group.
Turn on message moderation
-
Sign in to Google Groups.
-
Click My Groups.
-
Choose a group.
-
Near the top right, click Manage.
-
On the left, click Settings
Moderation.
-
Select your desired settings. You can review every message or messages from new members or non-members, and choose settings for rejected posts.
-
Click Save.
Only people who have the "Approve messages" permission can moderate posts. Learn more about permissions.
Approve or deny pending posts
You can approve or deny posts before they appear to the group. If posts aren't approved within 7 days, they'll be deleted.
-
Sign in to Google Groups.
-
Click My Groups.
-
Choose a group.
-
Near the top right, click Settings
Manage messages.
-
To read a post, click the title.
-
Check the box next to the post.
-
At the top of the screen, select an option:
-
To approve the message, click Approve
.
-
To approve the post and automatically approve all future posts by that author, click Trust
.
-
To ban the author or authors from the forum and report the message as spam, click Spam
.
-
To block the post, click Remove
.
-
Block people from replying to posts
You can create a new topic and prevent people from replying to it if you don’t want responses. You can do this if:
-
You're the owner of the group or have permission to lock posts AND
-
The group is a web forum (not an email list)
To block replies to a new topic: While you're creating the new topic, check the box next to "Lock."
<source: https://support.google.com/groups/answer/2466386?hl=en&ref_topic=2458761>