title: Detect email client where email is send
body: <p>We are create an Outlook plugin.
  User can using multi email client on multi device to sending email. 
  Then, all email send will sync to Send folder on Outlook.
  For some reason, we must to know what email have send by using another email client than Microsoft Outlook. </p>
  
  <p>Is it possible on MailItem class?</p>