Manage External Mail Sent to Groups
Owners have the ability to enable or disable non-members from sending messages to your Office 365 Group.
- In a web browser, navigate to portal.office.com, sign in, select Outlook.
- Under the Groups section, select the name of the group.
- In the top right corner of the window, click on the Gear Icon to open the Settings section.
- Select Edit Group.
Allow non-members to send to your Group
- Check off the Let people outside the organization email the group box
Disable non-members from sending to your Group
- Uncheck the Let people outside the organization email the group box