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

Issues symptoms

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

Resolution steps

Sometimes the default settings of Microsoft 365 accounts block automatic email forwarding as part of their outbound spam protection. For example, you receive a bounce message containing, 550 5.7.520 Access denied, Your organization does not allow external forwarding to be sent to your Microsoft 365 inbox when the error occurs.

To change the outbound spam protection settings

• Contact your Microsoft 365 administrator to allow automatic external forwarding for any Zendesk support address. For more information, see the Microsoft article: Control automatic external email forwarding in Microsoft 365.
• Enable automatic forwarding for all mailboxes in Microsoft 365 or only for the mailboxes forwarding to Zendesk

Note: Rules or spam policies of Microsoft 365 may affect external forwarding. If the issue continues after you change your outbound spam protection settings, contact Microsoft 365 Support for more help.