Is your feature request related to a problem? Please describe.
Sometimes it's just annoying when you get warnings in IDE because of @Nullable in ConfigurationSection#get(String, Object) and `ConfigurationSection#getString(String, S

The email feature is very cool, but sadly lacks the ability to unregister these emails, even through API.

This is very problematic because it means the user cannot ever sell the account or transfer ownership after registering an email.

Another issue is they can't ever remove an unwanted email when they add more then one.