3.1.5.5 Autodiscover Server Errors

If the server returns an Autodiscover response (as specified in section 2.2.4) that contains an Error element (section 2.2.4.1.1.3), the client SHOULD retry the HTTP POST request using the next URI in its list of potential Autodiscover server URIs. For an example of an Autodiscover response that contains an Error element, see section 4.5.