Open the inbox, and then click unread as shown in the below screenshot. That’s it check and delete unwanted mails.
Filter Unread Emails in Yahoo Mail BetaOpen Inbox and click on square shaped purple icon. It will display unread mail list. 
How to Sort Unread Emails in Yahoo Mail?
Filter Unread Emails in Yahoo Mail Classic
Open the inbox, and then click unread as shown in the below screenshot. That’s it check and delete unwanted mails.Filter Unread Emails in Yahoo Mail Beta
Open the inbox, and then click unread as shown in the below screenshot. That’s it check and delete unwanted mails.
Filter Unread Emails in Yahoo Mail Beta
