interval = int(round(msg_num/3))
    qs1= NewsletterMsgActive.objects.order_by('id')[:interval]
    t1 = Worker(qs1)
    t1.run()
    qs2= NewsletterMsgActive.objects.order_by('id')[interval:interval*2]
    t2 = Worker(qs2)
    t2.run()
    qs3= NewsletterMsgActive.objects.order_by('id')[interval*3:]
    t3 = Worker(qs3)
    t3.run()
    while not t1.complete or not t1.complete or not t3.complete:
        time.sleep(5)