Question about Outlook Express

I have followed the instructions on the Virgin website and on my Outlook 2013.  Once I have put in all the information, changed the advanced settings, enabled IMAP, Outlook says that it cannot find my email address.  I have done this about 15 times, rechecking my sign in by signing into my account via Virgin; the address and password I am inputting is correct.  I've logged out of Virgin when I do it, I've rebooted and that's as far as my IT knowledge goes.  I'm hoping I have missed something simple (this would seen likely!) and that some one can point me in the right direction.