Win8.1 Preview Mail, Calendar and People App Update Preview

Windows 8.1 Mail Mail Application

Windows 8.1 Mail Mail Supports more convenient multi-selection methods for batch operations, drag and drop support, multi-window Snap View mode, direct Skype conversation, and background color on the left sidebar .

The Windows Mail team also positioned the mail application as "Windows® Outlook.com client", and added Sweep cleanup, similar to Outlook.com's cleanup function; also has Outlook.com social and Press release category.
Windows 8.1 People

Windows 8.1 People network will also receive major updates. From the current interface, the user's first screen and contact information are updated, and the initial name of the contact name is filtered. It will also change. Below is the interface for the contact profile.
Windows 8.1 Calendar Calendar

Windows 8.1 Calendar Calendar changes a lot less than mail and contacts. However, Microsoft will add a new view to the Windows 8.1 calendar, "Whats Next", similar to the calendar view, to display the next series of calendar items.

The Windows 8.1 Messaging application will be replaced by Skype.