Alex van den Bogaerdt writes:
<quote>
In both the enterprise and the "new address" cases, information
hiding (and sometimes security) considerations argue against exposure
of the "final" address through the SMTP protocol as a side-effect of
the forwarding activity. This may be especially important when the
final address may not even be reachable by the sender.
</quote>
You are warping a statement about protecting the *destination* address
into an argument about the *sender* address. It doesn't apply.
RFC2821 does have this to say though, in section 4.1.1.3:
<quote>
For example, mail received at relay host xyz.com with envelope
commands
MAIL FROM:<userx(_at_)y(_dot_)foo(_dot_)org>
RCPT TO:<@hosta.int,@jkl.org:userc(_at_)d(_dot_)bar(_dot_)org>
will normally be sent directly on to host d.bar.org with envelope
commands
MAIL FROM:<userx(_at_)y(_dot_)foo(_dot_)org>
RCPT TO:<userc(_at_)d(_dot_)bar(_dot_)org>
</quote>
Note that the MAIL FROM is NOT changed. The section goes on to give
two other examples with the MAIL FROM not changed.
Nothing in RFC2821 or any other RFC I know of depicts the MAIL FROM as
anything other than the original sender except in the case of mailing
lists.
Trying to depict preserving the sender when forwarding mail at the
recipient's request as somehow forging the sender is simply not
correct. It's also not politic to call people forgers when they are
the very people you need on your side.
Forwarding grew out of the UUCP email days when all email was relayed
through a series of sites. It has been a perfectly legitimate
activity, often even a public service, for decades. Unfortunately,
the openness that forwarding has utilized is being widely abused. It
is the abuse that is a problem, and forwarders like me are having to
adapt. But we are not and never have been forgers.
--
Dick St.Peters, stpeters(_at_)NetHeaven(_dot_)com
Gatekeeper, NetHeaven, Saratoga Springs, NY