When using Autodiscover to add a mailbox to Outlook 2016 the wizard takes a very long time to complete. This guide describes how to reduce the required time

We suspect the issue is that Outlook 2016's functionality forces the Autodiscover wizard to try the HTTPS URL multiple times. As Autodiscover is done through HTTP in our environment it can be helpfull to exclude HTTPS checks for Autodiscover. This can be disabled in the User Registry Hive. You will have to create the following DWORD value's in the following location:

 

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

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

DWORD's":

 

  • ExcludeHttpsAutoDiscoverDomain

    • Value = 1

  • ExcludeHttpsRootDomain

    • Value = 1

  • ExcludeScpLookup

    • Value = 1

  • ExcludeSrvRecord

    • Value = 1

 

The last two DWORDS are optional, but can only speed up the process when using our Hosted Exchange environment.

Note: When you use multiple Exchange Environments you might need to disable one of the exclusions to allow Autodiscover to work properly for the other environments. At that point you should change the DWORD value to 0.

Source: https://support.microsoft.com/en-us/help/2212902/unexpected-autodiscover-behavior-when-you-have-registry-settings-under-the-autodiscover-key

 

It's also possible to download and execute the attached regfile for Outlook 2016, this is executed on the Current User, run this register-file for every user.


Autodiscover-excludehttsp-outlook-2016-user.reg:

[HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Outlook\AutoDiscover]
"ExcludeHttpsRootDomain"=dword:00000001
"ExcludeHttpsAutoDiscoverDomain"=dword:00000001