A request from your reviewer

[Stephane Bortzmeyer]

On Fri, Apr 13, 2007 at 01:39:24PM +0100,
 Michael Everson <everson at evertype.com> wrote 
 a message of 13 lines which said:

> Will EVERYONE ***PLEASE*** edit your headers before replying and
> sending. I receive TWO copies of EVERYTHING most people send.

A solution would be to use the non-standard email header
Mail-Followup-To. See http://cr.yp.to/proto/replyto.html See also
http://archives.neohapsis.com/archives/postfix/2005-01/0396.html and
http://mercea.net/~exmh/html/exmh-users/1998-02/msg00077.html if you
like long IETF rants.

Another solution is to filter out duplicates. With procmail :

:0
{
        :0:$HOME/.duplicate.lock
        * ? formail -D 8192 $HOME/.duplicate.procmail-cache
        $HOME/.mail-duplicates
}