Unfortunately, this leaves up-to-date Outlook users disconnected when Autodiscover hasn’t been provisioned correctly by your company. This (unsupported) method now no longer works in Outlook 2016, Outlook 2019 and Outlook for Office 365 due to the removal of this legacy dialog since Outlook doesn’t support Exchange 2003 anymore since Outlook 2013.
In some part, this was due to the fact that you could still get basic Outlook-Exchange connectivity by using some legacy Exchange 2003 RPC over HTTP dialog in Outlook.
The Autodiscover service is a required service for Outlook-Exchange connectivity since Outlook 2007 and Exchange 2007 but for whatever reason, in some Exchange environments this still hasn’t been implemented correctly.
