Every web hosting will have an expiry date based on how long the hosting service or package is registered for. You are required to renew your hosting service prior to the expiry date in order to maintain your website and email accounts (if you setup one). Otherwise, your hosting service will expire and your website will go offline and emails will not work.
If your hosting service has expired for more than 30 days, the content for your website and emails be deleted and will not be restorable.