The problem must be with aol, as I've just sent an email from my hotmail account on my ipad and it has sent. I don't know how we'd put that right though ??!
I have the exact same problem. Had my ipad2 since August, no problems. This morning has stopped sending emails. My default email is AOL.
I've tried deleting the account and readding, I've plugged it into my laptop to make sure everything is up to date, which it is. And I've rebooted it, but the...