I set up my Btinternet account manually as a Yahoo account (as Btinternet is Yahoo based). Is yours Btinternet ? The settings that I've got are :
Name : my name
Address : email@example.com
Password : ...
Description : my name
And that was all I needed to set up, as it's Yahoo based it'a able to use the Yahoo default outgoing settings.
Yes you might as well delete it, there's no need having an unnecessary (and not working properly) account on the iPad - apart from anything else you might accidentally select it in the future and then try to send emails from it.