Despite what most think, an email address is NEVER yours, it always belongs to whoever owns the domain name (basically the bit after the @ sign) - they simply allow you to use it and offer to store and handle your emails for you subject to certain conditions - mostly that you pay them money!
As @Graham_A says above, VM only provide (now) @virginmedia.com addresses, and a few older legacy addresses and only then if you are also a VM broadband customer. But even if they didn't have the last stipulation, it just isn't possible for them to provide any other email addresses other than the ones they control.
