Re: DMARC: perspectives from a listadmin of large open-source lists

John C Klensin <john-ietf@jck.com> Mon, 14 April 2014 14:37 UTC

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Date: Mon, 14 Apr 2014 10:37:12 -0400
From: John C Klensin <john-ietf@jck.com>
To: Dave Crocker <dcrocker@bbiw.net>, Doug Barton <dougb@dougbarton.us>, ietf@ietf.org
Subject: Re: DMARC: perspectives from a listadmin of large open-source lists
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--On Monday, April 14, 2014 07:23 -0700 Dave Crocker
<dcrocker@bbiw.net> wrote:

> On 4/14/2014 2:14 AM, John C Klensin wrote:
>> There is a strong rule in RFC 5321 and its predecessor
>> forbidding anything but the final delivery system from
>> rewriting a local-part and it is there precisely because one
>> doesn't know what sorts of conventions and indicates were
>> begin used there.
> 
> 
> Just to avoid possible confusion about the implications of the
> above:
> 
>       Mediators, like mailing lists, take final delivery and
> post a new message.  In formal terms, it's legitimate for them
> to create a different rfc5322.From field, including one that
> looks like some sort of 'rewrite' of the one used by the
> original author.

Yes.

     john