Retrieving Outlook version & build for clients connecting to mailboxes in EXO
On Oct 31, 2017, RPC over HTTP will be deprecated in Exchange Online in favor of MAPI over HTTP, a modern protocol that was launched in May 2014. This change affects you if you're running Outlook 2007 because it won't work with MAPI over HTTP.
So how Can you Identify what version(s) of Outlook your users are connecting with? Well, thanks to Joel Ricketts (Support Escalation Engineer in CSS), this KB article has been updated with information on how to retrieve this information.