Outlook Email app on Microsoft Hololens seems like a redesigned version of the app available for Windows 10 devices. Microsoft has been building universal Windows apps which scale across platforms with simple tweak in code.
New features for Outlook email app in Microsoft Hololens
In a blog post, Microsoft says Outlook on HoloLens delivers a familiar experience to users who are already using the apps on Windows 10 PCs, tablets and phones.
Outlook app is available from Windows Store on HoloLens for all HoloLens Developers to test and build similar communication apps. Interestingly, HoloLens users can vertically resize the app for split view of mail and calendar just like on the desktop.