Microsoft's latest Windows 10 "Redstone 2" test build adds some new Outlook Mail and Calendar updates that will come to all Windows 10 users in the coming weeks.
Windows 10 build 14955, which Microsoft released to Windows Insider PC and Mobile testers in the Fast Ring on October 25, includes a new build of Outlook Mail and Calendar.
This update allows users to open email messages in a new window; supports Quick Actions directly from new email notifications and adds support for @ mentions (like some other versions of Outlook do).
There are also a number of fixes in this latest build, including a fix that allows some user who had issues signing into various Microsoft apps to sign into them. It also includes fixes for Precision Touchpads on PCs and quite a few other issues.
Windows Phone users running the Insider builds who were stuck on the 0% download issues should not encounter this issue any longer, as of this build, according to today's blog post about 14955.