Method: Set ajax as fail.
Method: Add snackbar.
Method: Get and set request.
Method: Send ajax response.
Method: Prepare template for email body based on event type.
Filter Hook: No description
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.
Method: Get email ids of user. If email passed then add it to email property.
Method: Send emails.