If it is your primary address - ie the one you use to log into My Virginmedia, then no, it can't be deleted. If it is a secondary address you can delete it in My Virginmedia.
If an address becomes too difficult to use then just don't check it. After 150 days of it being unaccessed VM will close it for e-mail purposes and it cannot be revived again. If that happens to be your primary address it remains valid for logging into My Virginmedia.
I'm a Very Insightful Person, I'm here to share knowledge, I don't work for Virgin Media. Learn more
Have I helped? Click Mark as Helpful Answer or use Kudos to say thanks