Exchange 2013 Autodiscover and Outlook Provider

Exchange 2013 Autodiscover and Outlook Provider

In earlier version of exchange like 2007/2010 there are three Outlook provider used for autodiscover and Outlook Anywhere

Where Internal Outlook Client uses EXCH and External Outlook Clients uses EXPR and third provider known as WEB

• The EXCH setting refers Exchange RPC protocol that is used internally which provides the internal URLs for the Exchange services 
• The EXPR setting refers Exchange HTTP protocol that is used by Outlook Anywhere which provides the external URLs for the Exchange services
• The WEB contains the URL for Outlook Web Access for the user which is not in use.

Whereas in Exchange 2013 there is no longer directly uses EXPR/EXCH Outlook Provider.

• Exchange 2013 uses two different EXHTTP providers for internal and externa respectively for Exchange 2013 user mailbox which are dynamically generated.
• It will process and use them on getting the Internal EXHTTP settings first and External EXHTTP settings second.
• In order to support EXHTTP Outlook provider the minimum supported client versions are as follows

1. Outlook 2007 SP3, 12.0.6665.5000
2. Outlook 2010 SP1, 14.0.6126.5000
3. Outlook 2013 RTM

Note: To check Outlook Version look at Outlook.exe file in the Windows Explorer

How Outlook Autodiscover Works

How Outlook Autodiscover Works

Outlook 2007/2010/2013 uses the autodiscover function for the following list of information

• The user’s display name
• Separate connection settings for internal and external connectivity
• The location of the user’s Mailbox server
• The URLs for various Outlook features that govern functionality such as free/busy information, Unified Messaging, and the offline address book
• Outlook Anywhere server settings

All the above information is taken in XML file and provided to the Outlook client by using the following method

• SCP lookup
• HTTPS root domain query
• HTTPS Autodiscover domain query
• HTTP redirect method
• SRV record query
• Local XML file
• cached URL in the Outlook profile (new for Outlook 2013)

To disable the autodiscover functionality of the Outlook add the key and make it as 1 under the following registry path

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

• PreferLocalXML
• ExcludeHttpRedirect
• ExcludeHttpsAutoDiscoverDomain
• ExcludeHttpsRootDomain
• ExcludeScpLookup
• ExcludeSrvRecord
• ExcludeLastKnownGoodURL (only applies to Outlook 2013)

Enable Logging in Outlook and you trace the file OlkDisc.log located in %temp% folder to understand on how Outlook Autodiscover works