title: Mailx Configuration Without mailrc
body: <p>i am using mailx command in Red Hat,
  i use this command: </p>
  
  <pre><code>mailx -r 'boss@comp.com' -s 'Email Send' 'user@comp.com' &lt; file_body
  </code></pre>
  
  <p>I don't have a local configuration for SMTP Server
  I don't have for my user the ~/mailrc
  The mail is sent successfully but i don't know the way that it used...</p>
  
  <p>I am using the postfix configuration in /etc/postfix and i use their commands like mailq and so on.</p>
  
  <p>Which configuration it Use?? 
  Use it the /etc/resolv.conf where it found the smtp server?
  use it the route on /etc/sysconfig/network-scripts ????</p>