title: How to code for grouping email in conversations
body: <p>...similar to gmail !</p>
  
  <p>Now it's easy enough to lump them together when the subject is (almost) same with additional prefixes ( re:, re: re:, ... ) perhaps</p>
  
  <p>but you can include additional people when you reply etc. and they do show up in the original "conversation" thread</p>
  
  <p>i haven't looked at the headers in a while but wondering if there are additional X-?????? headers that're being used or are part of some RFC/convention somewhere</p>
  
  <p>any sample/example code that already does this would be great of course!</p>