Short and sweet and doesn't give us much to go on. Assumptions. This account was closed more than 90 days ago, or its an old virgin.net address when VM offered its ADSL or dial-up service. You are not a current VM broadband customer. And so the answer is you can't access it and VM will not help you. If it is getting spam or is otherwise compromised VM will only help to get it properly deleted.
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Why didn't you tell us this to start with? Saves all the guesswork and you'd have had a definitive answer. Pity that it is you are still out of luck. Accounts that have not been used for that long will have been closed down by VM automatically and their contents (on VM's servers) deleted. No chance of access or recovery. EA must have alternative recovery procedures.
Although HowardML has told you VM's policy, sometimes closure doesn't work the way they want it to work and the mailbox remains available. As you are a VM customer, the Forum Team (VM employees) can at least get it checked for you. They will reach this thread in a few days and can advise you for certain.
Some info that will help them: What result do you get if you enter the address at mailtester.com ? (don't post your address, just the result) - valid means there is a possibility, invalid would mean it is defunct.
When you sign in to your VM billing account, is the address linked to the account? It would show on the my profile tab (scroll down to my services) or on the manage accounts tab. (see photos) If linked, you may be able to reset the password and gain access. If not linked - please advise if you have moved house or had a break in your services - that might mean you have an orphan address.
These facts will help the Forum Team to discover if you have any chance.