Well, I remember if you don’t use your account for some period of time or so, then provider terminates it, and, in fact, having asked around all the majors - Gmail, Yahoo Mail, Hotmail and Twitter, that does seem to be largely the case. Here’s how it runs.,
Google will terminate your account in accordance with the terms of service if you fail to login to your account for a period of nine months is the phrase I was looking for along with the fact that people can actively delete their accounts.
Yahoo! was also most accommodating. The answer was very different though. It seems, with their service, that once your name has gone, it’s gone forever. As it stands, inactive accounts are not terminated and will lie idle indefinitely.
Accounts that are inactive for more than 6 months may be removed without further notice.