I don`t know about Virgin, but most ISP`s require you to log in, directly via their connection, every so often. The time varies from 30 days to 90 days, depending on the ISP. Some even need it to be from the same telephone number you registered with initially. If the account is not used after the required period it is suspended, and your e-mail address would be lost.
Maybe someone has had personal experience and can advise you better.