Yesterday while using Yahoo Mail, I was clearing out my Trash folder by clicking on the trash icon. The usual popup dialog asking me to confirm showed up so I clicked Okay.
At the time, I had only 4 items in the Trash folder, so when the dialog was taking a long time to delete 4 items I started to get worried. Once the busy dialog cleared, my INBOX was Empty! I just deleted all my email from the last 15 years!
By clicking near the Trash Can icon next the either the Spam or Trash folders, a dialog box for deleting All Emails for the Inbox shows up! It’s very easy to reproduce in Firefox 38.0 running on Ubuntu 14.04. Just click near the icon and you will get a dialog to delete everthing out of your inbox:
I’ve posted a feedback request to Yahoo about the problem, we’ll see if they will fix it and restore my email.