Use case: Use this procedure to configure delivery restrictions for a group. Adjusting delivery restrictions helps control who can send messages to the group – for example, limiting communication to internal users or approved senders only.
To configure delivery restrictions for a group, do the following:
- Open Group properties, select the Mailbox tab, and click Delivery Restrictions.
- Configure Accept messages from to allow messages from a limited list of users and reject all others.
- To reject emails from external (non-authenticated) users, select Require that all senders are authenticated.
- Configure Reject messages from to block messages from specific users and allow all others.
- Click OK twice to apply the settings.
Note: For hybrid groups, delivery restrictions can only be configured locally in the on-premises Active Directory. To propagate your changes to the Exchange Online distribution group, perform an Entra Connect synchronization.
ID:KB_025_HowToConfigureGroupDeliveryRestrictions
