The Windows Server Essentials and Small Business Server Blog has a post (and a video) on the email options which are supported in Windows Server 2012 Essentials.
First up we are told about an on-premises Exchange server, next Office 365 and finally third-party hosted email services.
An essential read for all users of Windows Server 2012 Essentials, which you can find here.
Microsoft MVP Philip Churchill's MS Windows Home Server Blog is one of the leading sources of breaking news and information, insightful opinion, and great tutorials regarding Windows Home Server. If you're an HP MediaSmart Server owner, this is a can't miss!