How to send out newsletter?

I've added messages in mass mailer & email was successfully added to queue. What should I do next? How to send the messages out to all members??

Select the message from the dropdown box in massmailer and select criteria below and click queue and the cron will send it  ..... 
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I am not seeing the members who are subscribed to the newsletter. And also I am not receiving the email after it is submitted to the queue. What else do I have to do?