A friend tells me on the old Yahoo Mail she used to use an option to select all unread mail in order to delete them all.
But in the new Yahoo Mail interface this option doesn't seem to exist. But is it maybe hidden somewhere?
These are the steps you can follow to delete unread messages but it's not a clean way but you've only this option to do so :
Change your view to "Sort by Unread". View is on the same row as the Delete button.
Here you have two options, you can either, click on the individual unread message or you can click on the select all check box and deselect all the read messages. Which ever that requires less clicking. Either way, you want to have only the unread messages selected.
and select "Delete"
To delete items showing in INBOX as unread
Using Yahoo 7 - If you right click on INBOX a drop down box will appear with
Mark as Read - Left click on this box and it's done.
They are deleted from your 'unread' without being seen by you. If you want to read them don't do this because you have no way of identifying which ones they were. They are now listed as 'read.'
If you need to delete the unread items within a specific folder then you can enter the command
click on the Search button. Select all by clicking the checkbox in the header and click Delete. This will delete all unread messages in the folder.
If you want to delete all the mails, regardless whether they are read/unread, just type
in:Foldername, search and delete.