Hi ITMA,
I move people's email addresses for a living. (Someone has to.)
You may be able to set up Virgin to forward your emails, but they are really under no obligation to keep that going when you leave them. I'm not saying that they won't do it, but don't depend on it.
It is best to get any new email address established with your friends, relatives, business contacts before you leave Virgin. (Preferably a couple of months overlap.) Don't forget to update banks, and places that you log into with your email address (Amazon, eBay, etc,).
Free options include: Gmail, Outlook.com, Yahoo.co.uk
The advantage of using them rather than your telephone provider is, as you are finding now, if you ever change telephone provider your email stays the same.
If you want something with your own domain e.g.
[email protected] (assuming it is available) then you can purchase it for about £5 - £6 p.a. A paid for email system need only cost £0.80pcm. on top of that. (As an example, I currently sell a ten user system with bottomless email for £1.83pcm - but I'm not on here to sell... so I won't tell you how to get it unless you p.m. me.)
Then there is a question of what you do with your historic emails... you may have few that you want to keep or 10s of thousands. You may be happy migrating that or you may need help.
I hope that helps.