Bypass Autodiscover step

Question

How can I bypass the step where the Autodiscover service of Microsoft Outlook checks for settings at https://domain.com/autodiscover/autodiscover.xml?

Context

Hi guys!

By default, Outlook sequentially checks for Autodiscover configuration services in five default locations; the second of such locations is https://domain.com/autodiscover/autodiscover.xml. This location is checked even before autodiscover.domain.com/autodiscover/autodiscover.xml.

A client of ours for which we manage a website at domain.com uses a remote Enterprise Exchange server at outlook.com. In principle, when his Outlook client automatically looks for Autodiscover settings at https://domain.com/autodiscover/autodiscover.xml, it shouldn't find anything, and move on to the next step, autodiscover.domain.com, which is correctly configured at the DNS level to point to autodiscover.outlook.com. However, the client does find some settings and fail; these settings turned out to be those of our hosting provider for domain.com, which are different from the desired settings at outlook.com.

We asked our web hosting provider to remove the URL https://domain.com/autodiscover/autodiscover.xml, but they refused. The reason is that domain.com resides on a shared machine, and cPanel only allows to disable the Autodiscover service server-wide. That is, it is not possible to remove the problematic URL for just one domain; I found out that this happens to be a well-known limitation of cPanel.

Could you please suggest a workaround for this perfect storm? Ideally, I would prefer a server-side solution, but at this point even a client-side registry hack would be welcome. I have found some on Server Fault, but none dealt with this step of the Autodiscover logic.

Thank you for your attention!

Not ideal, but a workaround is via registry on the client computers. (of course you may set this trough Group Policy)

In keys :

HKEY_CURRENT_USER\Software\Microsoft\Office\x.0\Outlook\AutoDiscover

and

HKEY_CURRENT_USER\Software\Policies\Microsoft\Office\x.0\Outlook\AutoDiscover

Note x.0 in the above registry path corresponds to the Outlook version (16.0 = Outlook 2016, 15.0 = Outlook 2013, 14.0 = Outlook 2010, 12.0 = Outlook 2007).

create the value :

ExcludeHttpsRootDomain

and set it to 1

Source en more information here :

https://support.microsoft.com/en-us/kb/2212902