Server 2012 R2 and Windows Essentials server include a feature called Anywhere Access that allows users to access their office resources through a feature called Remote Web Access. This is an evolution of the Remote Web Workplace that was previously available in SBS server products. The attached PDF document shows the process for connecting to the server resource and what information that you would need to follow. The text of the article is below as well.

How to use Remote Web Access in Server Essentials 2012 (link to PDF)