Why Autowired bean not creates new instance but does loaded from context?

I have simple scheduler.

public class MailSendScheduler {

    @Autowired 
    MailCollector mailCollector;

    @Scheduled(cron = "0/10 * * * * *")
    public void call() throws Exception {
        log.info("Method executed " + new Date());

        taskExecutor.initialize();

        for (int i = 0; i < 15; i++) {
                mailCollector.setText(Integer.toString(i));
            taskExecutor.execute(mailCollector);
        }
    }   
}

My config looks like this:

<bean id="mailCollector" class="ge.ddrc.school.mails.MailCollector" scope="prototype" >
            <property name="mailSender" ref="mailSender" />
    </bean>

Mail Controller is runnable class, and I log the integers in run() method.

@Component
public class MailCollector extends Thread {
  public void run(){ log.info() }
}

What do you think what will be result? It should be from 0 to 14 is not it? But not it looks like this:

2,2,4,5,14,14,14,14,14,14,14,14,14,14,14.

It seems that mailController is Singleton. I think it is not creating new bean. But WAIT , If I write this:

ApplicationContext context = new ClassPathXmlApplicationContext("spring/mail-config.xml");

        for (int i = 0; i < 15; i++) {
            MailCollector  mailCollector=(MailCollector) context.getBean("mailCollector");
            mailCollector.setText(Integer.toString(i));
            taskExecutor.execute(mailCollector);
        }

the output is like this: 1,2,3,4,5,8,9,6,7,10,15,13,14,12,11.` And it is correct too! why this happens?