Method: Add multiple template tags.

Method: Get default template for an email.

Filter Hook: Filter for adding default email template.

Method: Prepare template for email body based on event type.

Filter Hook: This filter allows overriding `$main_tags`. Which is used in main email template.

Filter Hook: Allows filtering email template after its prepared, passed be reference.

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.