[iMore Question]

My iPhone keeps downloading e-mails. Now has over 700. Is there a way to delete all without having to mark each?

[Just_Me_D]

You can't do what you're seeking to do via the native mail app. You can, however, login to your email provider's website via the Safari app on your device and mass delete them. Alternatively, you can logon via a computer and do the same thing.

[zerog46]

If your using ios7 you actually can now. Click edit, select all then trash.