Re: Mailman 2.1.16 [DMARC: perspectives from a listadmin of large open-source lists

Theodore Ts'o <tytso@mit.edu> Mon, 14 April 2014 21:01 UTC

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Date: Mon, 14 Apr 2014 17:00:59 -0400
From: Theodore Ts'o <tytso@mit.edu>
To: Brian E Carpenter <brian.e.carpenter@gmail.com>
Subject: Re: Mailman 2.1.16 [DMARC: perspectives from a listadmin of large open-source lists
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References: <20140414024956.26078.qmail@joyce.lan> <534B524F.4050206@dcrocker.net> <alpine.BSF.2.00.1404132327560.26258@joyce.lan> <E0B7196CB2603B80BBEC21AF@JcK-HP8200.jck.com> <alpine.BSF.2.00.1404132346420.26386@joyce.lan> <1EBDF5239EEE5202D3837D25@JcK-HP8200.jck.com> <534B9760.90301@dougbarton.us> <534BFA0D.7000404@meetinghouse.net> <CAL0qLwZdOORfasExjyc9BHDMYwR_gUk7NRiE7KFBWUC2Hae9jg@mail.gmail.com> <534C4794.5000600@gmail.com>
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On Tue, Apr 15, 2014 at 08:39:48AM +1200, Brian E Carpenter wrote:
> Murray,
> 
> On 15/04/2014 05:26, Murray S. Kucherawy wrote:
> ...
> > The DMARC proponents did engage mailman.   Version 2.1.16 includes support
> > for a setting that makes the operation of the list DMARC-friendly, though
> > likely in a way some people will find unpalatable. 
> 
> Please tell us more about that.

>From what I can tell, it has an option which you can replace the From
field with the original sender's from field with the mailing list's
e-mail address.   i.e., instead of:

From: Brian E Carpenter <brian.e.carpenter@gmail.com>

it would instead be;

From: IETF <ietf@ietf.org>

Any SPF or DKIM fields would also get stripped, and the original from
field would be moved elsewhere (it's not clear from reading the
description whether it's to some other header field, i.e.,
"X-Original-From" or to the body of the e-mail.



The solution I would prefer is one where mailman look up the DMARC
record, and if it's p=reject, it could rewrite the email from:

From: Brian E Carpenter <brian.e.carpenter@yahoo.com>

to something like:

From: Brian E Carpenter <brian.e.carpenter@yahoo.com.INVALID>

(or maybe instead of yahoo.com.INVALID, it should be "yahoo.com.BREAKS.MAILING.LISTS" :-)

    	  	     			   	  - Ted