Microsoft Outlook
Ctrl + q = Read; Ctrl + u = unread
To view message headers:
Double-click to open the email in its own window. Select File » Properties.
Change Outlook's Default File Save Location
Change Outlook's Default Template Save Location
How to Take a Vote with Outlook 2013
— also works with Outlook 2016
How to Find Folder Paths in Outlook Mailboxes
Create Folder Shortcuts in Outlook
Keep Your Meeting Requests in Your Inbox
Path:
C:\Program Files\Microsoft Office\root\Office16\OUTLOOK.EXE