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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!

Guido Walter Pettinari
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    You can control Autodiscover behavior with Group Policy if the client machines are domain joined or you can use the Registry if they're not. - https://support.microsoft.com/en-us/kb/2612922 - https://support.microsoft.com/en-us/kb/2212902 – joeqwerty Feb 16 '16 at 13:07
  • Thank you for your comment @joeqwerty! Do yo think it would be possible to apply a domain-wide Group Policy without having to configure each single email client? I would like to avoid having to configure each device in the organisation manually. – Guido Walter Pettinari Feb 16 '16 at 16:42
  • The first link in my comment is about disabling one or more methods via Group Policy. – joeqwerty Feb 16 '16 at 20:48

1 Answers1

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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

JFL
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  • It should be noted that this will only fix Outlook clients, and only Windows ones at that. Mobile devices will still require valid Autodiscover, or a deployed configuration profile through MDM to function properly. – blaughw Feb 16 '16 at 17:36
  • Thank you for the answer! I would definitely upvote it if I had enough reputation. @blaughw, would your solution (deployed configuration profile through MDM) work with a hosted Exchange server? Does it require to register each device or is it automatically applied to any device in the domain? Thank you :-) – Guido Walter Pettinari Feb 16 '16 at 18:01
  • Mail configuration will be different between Apple and Android devices. Each MDM (Mobile Device Management) platforms is a bit different. If this is a requirement for you, I would recommend doing more research here. Pushing a configuration profile is a step to simplify connections for end-users. This is definitely possible for Hosted Exchange, as along as the service is available from the internet. – blaughw Feb 16 '16 at 18:05
  • I ended up moving the the domain on a dedicated server where I could disable cPanel's Autodiscover service. Expensive, but fast and effective :-) Thank you all for your input! I accept JFL's question because it gives a way to solve the problem, although not an ideal one, and it mentions Group Policy. – Guido Walter Pettinari Feb 17 '16 at 17:09