There is a more pressing issue here... For some reason, your phone is failing to send outgoing emails :/
You may want to long press the emails that are not sending and select DELETE from the menu that pops up to at least get rid of them, but I would recommend switching to an Email app other than the stock email app. I had the same issue, where my phone, on Android 4.0.4 would not send emails. I switched to MailDroid PRO, and now it works flawlessly.
Good luck!