M365 Mailflow Domain Settings/Status

If you don't have any Microsoft 365 domains set up for Sophos Gateway, do as follows:

1. Click the General Settings icon .
2. Under Email Domain Setup, click M365 Mailflow Domain Settings/Status.
3. Click Setup Domains and Policies for M365 Mailflow.
4. If you haven't synchronized your Active Directory, do it now. If you've already synchronized your users and mailboxes, click Proceed to Next Step.

5. In Add Domain, enter your domain details and click Setup M365 Mailflow.

   Note

   If you want to protect only a subset of mailboxes from the domain, create a new group in Microsoft 365 and add the mailboxes you want to protect. When you synchronize users and groups, this group is also imported. See Microsoft 365 email groups.

6. Follow the instructions to set up your domains and mail flow rules. After you add your domain, you're redirected to Microsoft for authentication and permission granting. You must grant these permissions to create the necessary applications and mail flow rules.

   When the migration or addition of domains is complete, the M365 Mailflow Domain Settings/Status screen appears, showing your list of domains.

7. To set up mail flow rules for these domains, click Connect and follow the instructions.

   You're redirected to Microsoft to authenticate your domains and grant permissions.

   You must grant these permissions in order to create a Microsoft 365 connector and the necessary applications and mail flow rules in your Microsoft 365 environment.

   Note

   When you've granted the permissions, the connector creation process can take up to ten minutes.

   If you already have mail flow rules set up on your Microsoft 365 domain, you see the Pre-existing Mailflow Rules Found message. To deal with this, see Fix conflicts with Microsoft 365 rules.

   When your Mailflow protection is set up, a success message appears.

8. You can click Run a Quick Test to verify your Mailflow setup. Enter an email address to receive the test message. The test may take a few minutes.

   Warning

   After the connection is set up, Microsoft may continue to create other connections and resources in the background. If the quick test fails, wait at least 15 minutes and run it again before you start troubleshooting. See Troubleshoot Sophos Mailflow.

   The domains appear in M365 Mailflow Domain Settings/Status with a green check mark.

If you're already using Sophos Gateway on your Microsoft 365 domains and want to set up Sophos Mailflow rules on a new domain, or migrate your existing domains to Sophos Mailflow, do as follows:

1. In Sophos Central, click the General Settings icon .
2. Under Email Domain Setup, click M365 Mailflow Domain Settings/Status.

3. In the next screen, do one of the following:

   • If you're migrating a domain from Sophos Gateway to Sophos Mailflow, click Copy Existing M365 Domains. You confirm your choice, then we copy any Microsoft 365 domains we've detected.
   • If you're adding a domain to use with Sophos Mailflow for the first time, click Setup Domains and Policies for M365 Mailflow and follow the instructions.

4. When the migration or addition of domains is complete, the M365 Mailflow Domain Settings/Status screen appears, with your list of domains.

5. To set up mail flow rules for these domains, click Connect and follow the instructions.

   You're redirected to Microsoft to authenticate your domains and grant permissions.

   You must grant these permissions in order to create a Microsoft 365 connector and the necessary applications and mail flow rules in your Microsoft 365 environment.

   Note

   When you've granted the permissions, the connector creation process can take up to ten minutes.

   If you already have mail flow rules set up on your Microsoft 365 domain, you see the Pre-existing Mailflow Rules Found message. To deal with this, see Fix conflicts with Microsoft 365 rules.

   When your Sophos Mailflow protection is set up, a Success! message appears.

6. You can click Run a Quick Test to verify your Sophos Mailflow setup. Enter an email address to receive the test message. The test may take a few minutes.

   Warning

   After the connection is set up, Microsoft may continue to create other connections and resources in the background. If the quick test fails, wait at least 15 minutes and run it again before you start troubleshooting. See Troubleshoot Sophos Mailflow.

   The domains appear in M365 Mailflow Domain Settings/Status with a green check mark.

When the migration is complete, verify that your mailflow rules are working.