title: SMTP server error: Verification failed for 550-No Such User Here 550 Sender verify failed
body: <p>I'm using 
  <a href="http://coffee2code.com/wp-plugins/configure-smtp/" rel="nofollow noreferrer">Configure SMTP</a> plugin for wordpress, when I used it in a local server (localhost) it works properly and send me the test email which confirms that it is working. But when I used it in a hosting site (I used Hostgator) it gives me an STMP error. <img src="https://i.stack.imgur.com/Zy1nC.png" alt="enter image description here"></p>
  
  <p>What is the possible cause of this error? and what is the possible solution?</p>
  
  <p>Thank you.</p>