You can use both, but obviously not at the same time. When you move providers, change your old Virgin SMTP address in your email client (Outlook Express, etc.) for that of your new email provider's SMTP address, that will [usually] allow you to use your old provider's (Virgin) email address with your new provider. Most providers will keep your account open if you sign into your account every now and then, usually every 60 to 90 days. Keep your old dialup modem to do that.