Since no one else seems to be asking this, there must be something in the zoho mail interface that I am failing to see.  

Not looking for an automatic method. Instead, when I sort email by sender, I want to be able to select all emails from a sender and delete them with minimum of key strokes. I've tried holding down shift while selecting -doesn't work. I've tried using "find" to filter all displayed headings to be from one sender -but there is no "delete all" option.

Ideally, I would be able to select one email at the top of the find results, and hold shift key as i select an email at the end of the results -thereby selecting all, and then just hit a delete button.

So far, it seems I have to click on the check box for each email to delete, then hit delete. But if I miss just one and click on the tiny envelope picture instead of the checkbox -everybox I've checked is immediately unchecked.

Probably something in the interface I can use to do this.