If you don't use the account for 60 days VM will suspend it and close it automatically after 90 days. Or you can go into My Virginmedia and delete it there - provided the address is not your primary e-mail address which you cannot close.
Superuser 2017/18 Use Kudos to say thanks Mark answer as "helpful" only when the problem is solved Please don't send me private messages unless I ask you to. I do not work for VM. The advice I give is based on my best understanding of VM policy and practice. You rely on it at your own risk.