Good morning. It is another fine day in support. I wanted to share an issue that I have seen a couple of times and want to have it handy for future reference. I had a customer with an SBS (Small Business Server) 2011 install. He was adding in Outlook 2016 clients, but could not get any of them to connect with autodiscover. One key piece of information in this case is that Outlook 2010 and 2013 clients work fine. With this in mind I checked Google. I found quite a few articles pointing to disabling MAPI/HTTP. This should not keep Outlook 2016 from connecting as it will drop down to RPC/HTTP.
In the end I setup an Outlook profile with IMAP. I was then able to get into Outlook and run an autodiscover test. When I ran the test I was able to get the error code from the server. Here is what I saw:
Attempting URL https://myserver.mydomain.com/autodiscover/autodiscover.xml found through SCP
Autodiscover to https://myserver.mydomain.com/autodiscover/autodiscover.xml starting
GetLastError=2147954402; httpStatus=0.
Autodiscover then proceeded to try the default path and failed. I did a search on this error code and found the following Microsoft article. My customer was running the latest version of Outlook though. I ended up doing the workaround at the bottom. Here it is.
- Open Registry Editor.
- Locate and then click the following registry subkey:
HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Outlook\Autodiscover
- On the Edit menu, point to New, and then click DWORD Value.
- Type ExcludeHttpsRootDomain, and then press Enter.
- On the Edit menu, click Modify, type 1 in the Value data box, and then click OK.
- Exit Registry Editor.
Outlook immediately worked after this, and much faster.
I hope this article has been informative. If you have anything to add or just want to comment, please do so below.
Glennopedia 
You don’t get the comments you should . The kind of handy tips, tricks and real-life experiences you feature are – IMO – worth more than a dozen MS official pages.
This is the kind of blog that’s short, to the point and actually *useful*.
This Autodiscover Outlook 2016 fail is a gem – and I was referencing one of your older posts re WSUS on SBS the other day – handy !
Thanks !
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Thank you for this tip.
We have an external user with Outlook 2016 that couldn’t connect to our Exchange 2010 server. “AutoDiscover internet timeout” and “GetLastError=2147954402” were the errors we see at the Test AutoConfiguration log.
Then I created the registry key as there was no Outlook key created. That didn’t work. But, after I undo that (deleted the key I created)… voila…. Outlook connected.
Thank you.
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