You can choose who has access to email-in a message to a group, or shut the service off, from the Custom Email Options on the Group Settings page:
To get there, go to the group page and click on Group settings
Scroll down and expand the Custom Email Options and then find the EMAIL RESTRICTIONS section:
- Restricted email-in access: This selection allows only users who are in your network email-in to groups
- Unrestricted email-in access: This selection allows users who do not belong to your Regroup network to post a message to the group, as long as they have the email address for the group. This can be useful for community outreach notifications and for emergency response coordination.
- Disable this feature: This selection disables the ability to email-in a notification to the group completely