O365 E1 is the “lightest” version of the Enterprise-level plans. In the rest of this article, I’ll give you an introduction to each of the three versions, a more detailed comparison table, some special considerations for different industries, and a video overview.

The short table below gives you a quick overview. With each successive level, you get more features - but what is included, exactly? Microsoft Office 365 comes in three different flavors for Enterprise: E1, E3, and E5.