3825655 - How can I fix the issue "smtp;550 5.7.133 resolver.rst.sendernotauthenticatedforgroup" when a user doesn't receive emails from Concur due to this error?

The user is not receiving emails from SAP Concur and when checking email logs the error shows "smtp;550 5.7.133 resolver.rst.sendernotauthenticatedforgroup; authentication required; delivery restriction check failed because the sender was not authenticated when sending to this group"

smtp;550 5.7.133 resolver.rst.sendernotauthenticatedforgroup; authentication required; delivery restriction check failed because the sender was not authenticated when sending to this group , KBA , CON-CA-ADM , Administration , Problem