What do you see when you first open Yahoo! Mail? A Welcome page. Welcome! Underneath, you’ll see the list of folders and the number of unread messages in those folders. If you do not have any unread messages since your last login, you will see ‘You have 0 unread messages.’
Click Inbox. You can also click Inbox at the top of your folder list to the left. Or you can click on any other folder if you’re looking for a message somewhere other than your Inbox.
A list of emails opens in the main window. Click on the Subject of any one of them to open it. Bingo! Now you can read it.
After you've read a message, its info line (sender, Subject, Date/time) will no longer appear in bold in the list of messages in the folder. Only the info lines of unread (fresh!) messages will appear in bold.