Find Email Owner & Disconnected Phone Owner?

I am not a lawyer or business interest but a private person doing a favor for a family member who does not have a computer. I have an email address associated with a disconnected phone number. This address is no longer active as of a few months ago. Would you be able to trace how this address was paid for and in whose name the method of payment is registered? Also, is there a way to legally retrieve the content of the emails relative to this address? Please advise if either of these things can be done and what would be the cost.

How To Trace Gmail Sender?

How I trace the Sender of Email. email comes from gmail Account.