The Delivered-To cannot be considered
exclusively authoritative, as it is
commonly overwritten due to virtual
routes during mail delivery.
Its primary purpose is to avoid mail
loops, so it cannot be fully trusted
here.
lp bug: https://launchpad.net/bugs/1085488 fixed
bzr revid: odo@openerp.com-20121218122935-vbcld3vrl260z96m