I am always amazed by the amount of customers running Exchange 2007 or Exchange 2010 and NOT using Autodiscover. Their response is always “we don’t need it” and “we configure the Outlook profile manually”. In Exchange 2007 and Exchange 2010 you can get away with this (you cannot with Exchange 2013 and Autodiscover is mandatory) but when you want to implement a hybrid scenario with Exchange online you really need Autodiscover since Exchange Online uses Autodiscover to find relevant information regarding your on-premises Exchange environment.
Recently a customer with Exchange 2010 wanted to build a hybrid environment with Exchange Online, and one of my first findings was the lack of Autodiscover. So, after configuring their Exchange environment and creating the necessary DNS records Autodiscover was working properly as shown in the following picture: