[73992] in North American Network Operators' Group
Re: Spammers Skirt IP Authentication Attempts
daemon@ATHENA.MIT.EDU (Stephane Bortzmeyer)
Fri Sep 10 03:58:22 2004
Date: Fri, 10 Sep 2004 09:55:55 +0200
From: Stephane Bortzmeyer <bortzmeyer@nic.fr>
To: Robert Bonomi <bonomi@mail.r-bonomi.com>
Cc: nanog@merit.edu
In-Reply-To: <200409082015.i88KFEdI004572@host122.r-bonomi.com>
Errors-To: owner-nanog-outgoing@merit.edu
On Wed, Sep 08, 2004 at 03:15:14PM -0500,
Robert Bonomi <bonomi@mail.r-bonomi.com> wrote
a message of 37 lines which said:
> Same thing applies for 'simple' forwarding via sendmails '~/.forward'
> mechanism. the mail server 'accepts' the mail from the original source,
> and then 're-sends' to the new destination. That re-send originates as
> the _forwarding_party_, WITH an 'envelope from' of that forwarding
> party,
Sorry, this is simply not true (sendmail, postfix, etc, always keep
the original envelope from when forwarding).
> An SPF check of the _immediate_ sender does *NOT* break forwarded
> mail.
Even SPF people say it:
http://spf.pobox.com/faq.html#forwarding
