Microsoft demonstrated its new Mail app for Windows 8.1 earlier this week during the Build keynote, but the company has started to share even more details about the upcoming overhaul. While the Mail app has gradually been getting better in Windows 8, the Windows 8.1 version opens up new features like drag and drop support, and sections to filter specific emails. During a Build session on Friday, Microsoft's Jeremy Epling walked through most of the new improvements in Mail.

Microsoft has altered the sidebar in the Mail app to include access to the categories that filter out emails like social updates or newsletters, and there's also options to pin folders. One new feature is the ability to pin a specific person to the sidebar and have the Mail app pull up all emails from that individual.

Other improvements include the ability to trigger Skype calls or messages from clicking on a contact within a mail. The existing Mail app in Windows 8 pushes you directly into the People app, and the new version aligns the user interface with the typical Outlook-style contact cards. Snapping has also been improved in Windows 8.1 and the new Mail app takes advantage of that. There are multiple views at different sizes, and you can also open up separate windows with individual mails side-by-side.

Unfortunately Microsoft isn't creating a unified mailbox with this new version, in part because of the various controls for selecting multiple emails and taking actions against them. The application isn't ready to be distributed just yet, but Mail, People, and Calendar, will all be updated alongside the final Windows 8.1 update due later this year.