Class: The email helper class.
Action Hook: Hook triggered before an email added to current sending list.
Method: Add user or email to current sending list.
Method: Add template tags.
Action Hook: Action triggered after adding email template tag.
Method: Add multiple template tags.
Method: Get default template for an email.
Filter Hook: Filter for adding default email template.
Filter Hook: Used for registering a default email template for an event.
Method: Add default new question email template.