bulk delete
Let's say you forget to select an email and you press delete button. Yahoo email server actually assumes that means I want to delete all 3000+ emails sitting in my email from beginning of time. Guys this is a dumb idea. No one wants to delete everything just because they forgot to select an item. Thankfully there is prompt but if you are distracted, you don't read what the prompt is saying and you press yes (because you think you are deleting the email that you intended to delete but forgot to select), poof! All your emails are gone.
This is DUMB DUMB DUMB idea. It's possible a VP who thought was very smart came up with it and shoved it down the team. But it is still a dumb idea. If you still have people working for you, remove it. There is zero value to this idea and only flaws. No one will miss this genius forget to select => All idea.