Anybody can buy a domain for the price of two coffees and have full control over their email addresses. There is no excuse for being locked in by google. Even if somebody wants to use google's UI, the emails can be forwarded to google, and at the same time backed up somewhere else in case google shuts down the account.
If you consider how vital one's email account is today, it's time to put down some money.
*edit: Buying a domain often comes with an email service. There is no need to run a mailserver.