This is why its always dangerous to use the ISP provided email, they do it to prevent you from leaving due to hassle of changing - vendor lockin
As mentioned create a gmail account for future use, set up the pop collection in settings to download virgin email ( and make sure virgin emails have label applied..see later).
To keep the account live, phone virgin customer service, explain that as no landline you dont want broadband but want to keep email, i know ukonline used to do an email only service for £2/month when people left their broadband etc.
If virgin say the account wont be closed for 6 months etc, get a timeframe from them, then from your new gmail account, email your address book to say that email address has changed, change all the registered addresses for amazon , BCUK etc. as time passes you should see less and less email come in with the virgin label.
How are you going to access internet from now on, from mobile data? or just from mobile phone?
Ive done all the above with numerous clients, its daunting but common problem, pm me with any questions
Al
UPDATE
It looks like they cancel after 90 days with no pay options to keep it alive, and because of the email recycling they do, very important to change email address used in all possible online accounts, i would change ASAP
http://www.choose.net/media/guide/faqs/email-address-switch-broadband.html
http://community.virginmedia.com/t5/Email/Can-I-keep-my-Virgin-net-email-address/td-p/2111676
http://community.virginmedia.com/t5/Email/keeping-email-address/td-p/1983712