title: How to maintain mail conversion (reply / forward / reply to all like gmail) of email using Python pop/imap lib?
body: <p>I've develop webmail client for any mail server.
  I want to implement message conversion for it — for example same emails fwd/reply/reply2all should be shown together like gmail does... </p>
  
  <p>My question is: what's the key to find those emails which are either reply/fwd or related to the original mail....</p>