Ultimately you can delete or close the account, (unless it's your master account). But if you do that you won't be abel to reactivate it in the future should you have a need for it.
Email accounts are controlled from here
https://autoreg.autoregister.net/cgi-bin/xtrmail You'll need to know your master username and password then you can add / delete your supplementary mailboxes.
AS far as I'm aware you have to have one ntl email, the master account. Its the way ntl might contact you if they cant be bothered to post. Of course you could just choose not to use it and not to collect email sent to it. Eventually the box will fill up and those sending will get bounced mail messages. If you haven't told anyone to use the addy what's the problem, it'll only be spam in there.
You can change the master email account name:
http://www.ntlworld.com/help/index_b...d_password.php . Changing will affect your ntl log on as well as the email account, but doen not appear to change the username / password of the ntl webspace (which remains as your original ntl allocated name / password). Choose something obscure not easily identified by dicionary type guessers. Thus name spelt with some numbers or
word.numbers.letters@ntlworld.com can be a good defence. Then never use the master account email for general correspondence, setting up other supplementary emails for general use (see first link above)