Access denied error message when setting up email forwarding in Office 365

Question

I am trying to set up email forwarding in Office 365 but I receive this error message: 550 5.7.520 Access denied, Your organization does not allow external forwarding. Please contact your administrator for further assistance. AS(7555).

How do I solve this?

Answer

In some cases, Microsoft 365 accounts default to block automatic email forwarding as part of their outbound spam protection. A bounce message containing the error 550 5.7.520 Access denied, Your organization does not allow external forwarding is sent to your Microsoft 365 inbox when this occurs.

To change the outbound spam protection settings, contact your Microsoft 365 administrator and ask them to allow automatic external forwarding for any Zendesk support address. For more information about this, see this Microsoft article: Control automatic external email forwarding in Microsoft 365.

Based on your organization's security policies, you can enable automatic forwarding for all mailboxes in Microsoft 365, or enable it only for the mailboxes you are forwarding to Zendesk.

Note that there may be other rules or spam policies on the Microsoft 365 side that affect external forwarding. If the issue persists after you make changes to your outbound spam protection settings, contact Microsoft 365 Support for further help.