title: how to set difference between reply and bounce email
body: <p>im building system, that tracks bounce emails and also when user reply back with message, then other user can read the message of this user.</p>
  
  <p>so far i have read from all the questions / answers, that bounce email can be sent to return-path or also to reply-to path. </p>
  
  <p>how can i tackle this issue? should i scan and see if its bounce email, if its not, then consider it as message email or there is some other way around it? </p>
  
  <p>checking for bounce email and then parsing for message, its just extra overhead, when system is getting lots and lots of emails from bounce or as messages.</p>