Function: Insert new subscriber.
Function: Get subscribers. Total subscribers count will be returned if no argument is passed.
Action Hook: Action triggered right after deleting subscribers.
Function: Delete subscribers by event, ref_id and user_id.
Function: Insert new subscriber.
Function: Get subscribers. Total subscribers count will be returned if no argument is passed.
Action Hook: Action triggered right after deleting subscribers.
Function: Delete subscribers by event, ref_id and user_id.