title: Detecting email client of the recipients
body: <p>We are planing to develop an extension for a software which will detect the email client software or interface of the recipients and report it.</p>
  
  <p>In many forums this subject is told that is not possible but in this site they claim that they provide a reporting in a large scale.</p>
  
  <p><a href="http://www.adestra.com/email-client-detection-with-messagefocus/" rel="nofollow">http://www.adestra.com/email-client-detection-with-messagefocus/</a></p>
  
  <p>I would be glad if someone could tell or show me a way to do it in any platform.</p>