Unread messages show a yellow, closed envelope icon, and show in bold letters in the folder listing; read emails display an opened, white envelope icon, and use normal text in the message list. You can manually mark emails as read or unread, and customize the number of seconds before which Windows Live Mail will marks them as read. A later tutorial will show you how to setup email rules to automatically mark certain emails as read when they arrive. Here's the same conversation, read and unread: 
Select one or more emails in the folder and click on the "Unread / Read" button in the ribbon to toggle these messages' Read status. You can do the same by right-clicking on a message (or a conversation!) and choosing "Mark as read
" / "Mark as unread
" - one of these two commands will appear grayed out (disabled) if all selected emails share the same status.
To mark an entire email folder as Read, right-click on its name in the folder listing (left), and choose "Mark all as read" from the context menu. To mark a folder as Unread, press Ctrl+A to select all messages, and Ctrl+Q once or twice to change their status. A folder is already entirely read when no blue number appears between parentheses next to its name - in our screenshot, there are 44 unread messages in the inbox, none in the Junk email folder.
Useful keyboard shortcuts:
• Hit Ctrl+A to select all emails in the current folder.
• Hit Ctrl+Q to toggle the Read/Unread status of the selected message(s).
• Hit Ctrl+U to show the next unread message in the current folder.
• Hit Spacebar to open it.
• Hit Ctrl+Shift+A to mark the entire folder as read (can't be undone).
When you have multiple email accounts setup in Windows Live Mail, quickly marking all emails as Read can be tedious without the following tip: instead of going through each inbox, just click on the "Unread email" virtual folder under Quick views. Click to select any of its message, and hit the Ctrl+Shift+A keyboard shortcut (or right-click and pick "Mark all as read"). Now, every single message in any of email accounts is marked as Read (for accounts setup as IMAP, this will affect their Read/Unread status on the mail server as well). The only messages left Unread after that are any new spam in the respective junk mail folders.
Tip: if you don't see "Quick Views" on the left, go to the Ribbon's View tab and click on the Quick Views button to toggle their visibility (a "persistent" setting, which Windows Live Mail will remember for the next session.)
To mark an entire conversation as read or unread, right-click on its header and choose Mark as read / unread from the context menu. When the thread itself is selected (blue highlight visible around multiple emails), you can also use the Ctrl+Q hotkey: 
Note: a conversation will appear as Unread as long as one of its messages is not read; mark it as read, and the entire conversation now shows as Read.
Click on the "Windows Live Mail
" menu (top left button), and go to Options > Mail: 
Select the "Read" tab at the top: the "Mark message read after displaying for [x] second(s)
" checkbox (first one) is checked by default, which means that Windows Live Mail will automatically mark messages as Read after the interval you specify in seconds: 
The default number of seconds Windows Live Mail waits before marking a message as Read is 1 second. Type a new interval in the text box, or use the up/down arrow buttons.
Click OK to save your new setting.
Final Tip: when you are in an email folder, you can filter out and hide read messages, and only show unread emails. Click on "Unread email" or "Unread email from contacts" in the top left corner, above the email folder listing:
