How do I disable Autodiscover after I migrate from on premise exchange?

When migrating from an in-house Exchange to Hosting.ca Exchange, you may encounter issues with Outlook still trying to retrieve Autodiscover configuration from local Active Directory.

Common symptoms:

  • public DNS is configured correctly;
  • in Outlook users get a password prompt for their old server (it may come up after prompting the user for Hosting.ca Exchange server or when the user is trying to access out of office assistant settings);
  • users cannot send folder sharing invitations;
  • running Autodiscover test in the user’s Outlook shows links to the old server;
  • a common fix to put a record for the Autodiscover server into the hosts file does not work

The cause for the issue is that Outlook is trying to access the Autodiscover settings from the local Active Directory. Below are a few possible fixes:

    • Adding Registry values for Outlook to exclude SCP object check
    • Setting Autodiscover settings through PowerShell
    • Fixing the local DNS records

1. Adding Registry values for Outlook to exclude SCP object check 

If you have users on the in-house Exchange server that are not supposed to be migrated to Hosting.ca at all, this can sometimes result in inability to really remove SCP object from Active Directory completely or update AutoDiscoverServiceInternalUri (because some users users are located on the old server). The fix also applies if you don’t have access to the in-house servers.

Note: Public Autodiscover DNS record should be pointing to Hosting.ca

The fix is to create the following Registry keys on necessary machines:
Navigate to HKEY_CURRENT_USER\Software\Microsoft\Office\x.0\Outlook\AutoDiscover (x.0 corresponds to the Outlook version: 16.0 = Outlook 2016, 15.0 = Outlook 2013, 14.0 = Outlook 2010, 12.0 = Outlook 2007) and create these DWORD values to excude all checks before ExcludeHttpRedirect which is used in Hosting.ca:

PreferLocalXML 0
ExcludeHttpRedirect 0
ExcludeHttpsAutodiscoverDomain 1
ExcludeHttpsRootDomain 1
ExcludeScpLookup 1
ExcludeSrvRecord 1

For Outlook 2010 version 14.0.7140.5001 and later versions, please also add the following DWORD:

ExcludeLastKnownGoodURL  1

For Outlook 2016 version 16.0.6741.2017 and later versions, please also add the following DWORD:

ExcludeExplicitO365Endpoint 1

Note: You may also need to add the same DWORD values to the following registry path: HKEY_CURRENT_USER\Software\Policies\Microsoft\Office\x.0\Outlook\AutoDiscover 

Original MS KB article: https://support.microsoft.com/en-us/help/2212902/unexpected-autodiscover-behavior-when-you-have-registry-settings-under