Unfortunately that will not be possible. Once Ntlworld email accounts are deleted they cannot be restored.
Your son will need to seek an alternative solution from Twitter.
________________________________
GrahamI'm a Very Insightful Person, I'm here to share knowledge, I don't work for Virgin Media, I'm a VM customer. There are no guarantees that my advice will work. Learn more
Have I helped? Click Mark as Helpful Answer or use Kudos to say thanks