You can choose to be notified when there is a pending message that requires your approval. To do this:

1. Go to your group home page. (Make sure you’re signed in.)
2. Click on Edit Membership at the top of the page, above the group’s name.
3. In the Email Notification section near the bottom of the page, select "Notify me when there are pending messages, photos, or memberships which require approval".
4. Click Save Changes.

Or...

1. Go to the My Groups page. (Make sure you’re signed in.)
2. Scan the Messages Pending column. If you have pending messages, the number of messages will appear here with a link to the Pending Members page.