I used to be with Blueyonder, now Virgin Media, so would I be correct in assuming that this is now your ISP? If so you'll probably need to do a bit of manual configuration in order to get your email working correctly on your iPad, sounds a bit difficult but worse than it sounds.
The info contained here should help.
iOS: Unable to send or receive email
Can’t Send Emails on iPad – Troubleshooting Steps
Setting up and troubleshooting Mail
Setting Up An eMail Account
Try this first - Reset the iPad by holding down on the Sleep and Home buttons at the same time for about 10-15 seconds until the Apple Logo appears - ignore the red slider - let go of the buttons. (This is equivalent to rebooting your computer.)
Or this - Delete the account in Mail and then set it up again. Settings->Mail, Contacts, Calendars -> Accounts Tap on the Account, then on the red button that says Remove Account.
No problem, glad I could help out, I remember they had a few tweaks you'd need to put in order to get the functions working. I use Gmail nowadays which ironically is what Virgin moved over to shortly before I moved out of the Virgin encachement area, and that set itself up on iOS devices without any issues.