For deleting unresponsive Yahoo email on iPhone, you need to go through these steps:
· At the first stage, you need to touch the Settings icon.
· After that you need to scroll down and then touch the Contacts, Mail, Calendars button.
· Next, you need to choose Yahoo account that has to delete.
· Then you have to touch the Delete Account button.
· Lastly, touch the Delete Account button once more for confirming that you want to eliminate your account from your iPhone.
If needed then connect with yahoo customer tech support help live chat.