http://permalink.gmane.org/gmane.mail.postfix.user/193458
is it intentional that "header_checks" intended to remove pre-existing X-Envelope-From and X-Envelope-To also removes the own by access maps prepended (looks also to be the case for policyd-headers like Received-SPF)
from *my* personal understanding of the docs i would assume that only by "smtp_header_checks"
