MAPIoverHTTP was originally released with the update KB2899591 (http://support.microsoft.com/kb/2899591) for Outlook 2010, but the update was withdrawn a short time later. Microsoft has now released a new update. The update requires Service Pack 2 for Office 2010. The update for Outlook 2010 can be downloaded here:
http://support.microsoft.com/kb/2878264
MAPIoverHTTP is a new protocol for Exchange 2013 SP1, which offers some advantages and improvements over RPCoverHTTP. Here you can find details about MAPIoverHTTP:
https://www.frankysweb.de/exchange-2013-mapioverhttp/
