• Estimated time to complete: 5 minutes
  
  
• You need to be assigned permissions before you can perform this procedure or procedures. To see what permissions you need, see the "Accepted domains" entry in the Mail Flow Permissions topic.
  
  
• You can't create an accepted domain that has the same name as an already configured remote domain. For example, if you have fabrikam.com configured as a remote domain, you can't create an accepted domain for fabrikam.com.
  
  
• Before you configure an accepted domain, you must verify that a public Domain Name System (DNS) MX resource record for that SMTP namespace exists and that the MX resource record references a server name and an IP address associated with your Exchange organization.
  
  
• For information about keyboard shortcuts that may apply to the procedures in this topic, see Keyboard Shortcuts in the Exchange Admin Center.
  
  

Tip:
Having problems? Ask for help in the Exchange forums. Visit the forums at: Exchange Server, Exchange Online, or Exchange Online Protection

You may want to configure an accepted domain for a business unit with email servers outside your Exchange organization.

1. In the EAC, navigate to Mail flow > Accepted domains, select the domain you wish to configure, and click Edit .
   
   
2. In the Name field, enter the display name for the accepted domain. Each accepted domain for your organization must have a unique display name. This may be different than the accepted domain. For example, the domain Contoso.com could have a display name of Contoso Local Accepted Domain.
   
   
3. Select External Relay Domain. This option is for email is relayed to a server outside your Exchange organization.
   
   
4. Click Save.
   
   

To verify that you have successfully configured an accepted domain as an external relay domain, send a message from the accepted domain you’ve configured as an external relay domain, and verify that it is received.