Outlook 2016 autodiscover slow with hosted Exchange
We have a large amount of clients that use hosted Exchange for their email service. As we started to roll out Office 2016 we noticed that it was taking an extremely long time for the autodiscover to detect the account settings. In most cases it would be in excess of 10 minutes. As Outlook 2016 no longer lets you manually setup Exchange accounts it was extremely frustrating. The problem s caused by a bug in Outlook 2016. All hosted Exchange services use the HTTP redirection method for autodiscover to work correctly. However Outlook 2016 will try the HTTPS root domain and HTTPS autodiscover domain first. For some reason Outlook 2016 tries each of those methods 11 times at approximately 30 seconds each and this is what causes such a large delay. The below registry settings will force Outlook to go directly to the HTTP redirection method and allow the account to be setup nearly instantly.
Windows Registry Editor Version 5.00
Hopefully Microsoft will provide an update to resolve this issue soon.