(Pocket-lint) - A BBC investigation has found that some ISPs are charging exorbitant fees to customers to keep hold of their old email address when they switch away. 

BT charges £7.50 a month, Talk Talk £5. Sky says it will maintain addresses for free long-term. 

Ofcom responded to the BBC Moneybox programme - which Pocket-lint took part in - and said it would "consider whether we need to step in and take action," also adding "we can't see a reason why you should have to pay these amounts to keep your email address."

One listener told the BBC programme that they had paid £260 since leaving BT three years ago. 

If Ofcom does decide to mandate providers to reduce or bin such charges than it may have to implement a system similar to that used when we switch phone numbers between networks, although it could be that the original email address is kept live just so the emails can be forwarded to a replacement email address.

If you're in the situation where you believe you may end up losing your email address because you'll switch ISP, we recommend you take the hit now and switch your email across to a web based email provider. That way you can transfer logins across gradually over time. 

You can also import your ISP email into a service like Gmail, too. 

Writing by Dan Grabham.