The appointments on the Outlook.com monthly calendar disappear and are replaced by 3 dots.
Create appointment from email in Outlook on the web
Can you create an appointment or meeting using contents of an email message in Outlook on the web?
Undo Send feature in Outlook on the Web
Outlook on the web's new feature: Undo Send. It gives you a few seconds (up to 30 seconds) to change your mind.
Office 365 and Outlook.com: Interesting Calendars
A new calendar feature, called Interesting Calendars, is rolling out to Office 365 Exchange Online and Outlook.com users (on the new server). The current calendars offered are sports schedules.
Disable Conversation View in Outlook.com and Outlook on the Web
I love conversation view, most of the time. It makes it easier for me to follow message threads as all previous messages in the thread are together, regardless of which folder each message is stored in. Not everyone likes it and finding where to disable it isn't necessarily intuitive.
Calendar Insights Template for Excel 2016
A new feature for Office 365 email account is the Calendar Insights template for Excel. This is template creates a workbook connected to your Office 365 Exchange (or Outlook.com on the new server) calendar and analyses how much time you spend in meetings, the people you meet with the most, when your busiest time of the day is, and more.
Changing Outlook.com color schemes
How to change the colors used in Office 365 and (the new) Outlook.com's Outlook on the web.
Open Shared Mailboxes in Outlook on the Web
How to open shared Office 365 Exchange mailboxes in Outlook on the web (OWA).