I understand from Florence that all bounces are triggered by emails sent by the same person. If related to this, it could get nasty: http://www.pcworld.com/article/2141120/yahoo-email-antispoofing-policy-breaks-mailing-lists.html

Lodewijk

On Sun, Jul 16, 2017 at 3:23 PM, Florence Devouard <wmf-l@anthere.org> wrote:
Hello

The owners of the list just received a collection of notifications from mailman@lists.wikimedia.org

Topic: Bounce action notification

Typical message received

This is a Mailman mailing list bounce action notice:

    List:       Wikimediafr
    Member:     an email address
    Action:     Subscription disabled.
    Reason:     Excessive or fatal bounces.
    


The triggering bounce notice is attached below.

Questions? Contact the Mailman site administrator at
mailman@lists.wikimedia.org.

------

The attached document features

Sujet :
Mail delivery failed: returning message to sender

De :
Mail Delivery System <Mailer-Daemon@fermium.wikimedia.org>
Date :
16/07/2017 14:09
Pour :
wikimediafr-bounces@lists.wikimedia.org


This message was created automatically by mail delivery software.

A message that you sent could not be delivered to one or more of its
recipients. This is a permanent error. The following address(es) failed:

  An email address
    SMTP error from remote mail server after end of data:
    host gmail-smtp-in.l.google.com [173.194.66.27]:
    550-5.7.1 Unauthenticated email from yahoo.fr is not accepted due to domain's
    550-5.7.1 DMARC policy. Please contact the administrator of yahoo.fr domain if
    550-5.7.1 this was a legitimate mail. Please visit
    550-5.7.1  https://support.google.com/mail/answer/2451690 to learn about the
    550 5.7.1 DMARC initiative. r67si3673368qkr.391 - gsmtp

  An email address
    SMTP error from remote mail server after end of data:
    host gmail-smtp-in.l.google.com [173.194.66.27]:
    550-5.7.1 Unauthenticated email from yahoo.fr is not accepted due to domain's
    550-5.7.1 DMARC policy. Please contact the administrator of yahoo.fr domain if
    550-5.7.1 this was a legitimate mail. Please visit
    550-5.7.1  https://support.google.com/mail/answer/2451690 to learn about the
    550 5.7.1 DMARC initiative. r67si3673368qkr.391 - gsmtp

etc. etc. etc.

At the end of all of which, I see

------ This is a copy of the message, including all the headers. ------

Return-path: <wikimediafr-bounces@lists.wikimedia.org>
Received: from localhost ([::1]:36576 helo=fermium.wikimedia.org)
	by fermium.wikimedia.org with esmtp (Exim 4.84_2)
	(envelope-from <wikimediafr-bounces@lists.wikimedia.org>)
	id 1dWiMp-0004Q5-F6; Sun, 16 Jul 2017 12:09:43 +0000
Received: from sonic303-23.consmr.mail.ir2.yahoo.com ([77.238.178.204]:41383)
 by fermium.wikimedia.org with esmtps
 (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.84_2)
 (envelope-from <omorand@yahoo.fr>) id 1dW8AO-0005kw-U0
 for wikimediafr@lists.wikimedia.org; Fri, 14 Jul 2017 21:30:29 +0000
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yahoo.fr; s=s2048;
 t=1500067827; bh=H0kKlQUk5veAFbi03/U9y+O19wVtODUQh3qxSVcacZk=;
 h=Date:From:Reply-To:To:Cc:Subject:References:From:Subject;
 b=o5jowvpe5tn4x6xMBXvjwoJuwMsrmu9BXygb+TXyWCoCX27aOoq2OmCl5vH3kE1fEdyF78ABFmZ+GflVUv1mjgz7zbjtHcuaFRC4XMI7NdFTle2sPwBZV+QRzka07uFFJ1+HgHDTGeaCMy5FhU9F4u3227XNYShb/CJ9ktPw74izlXvnBtyPmVwbomKq0I92pyXtA9ZZjL65Kv3pANQkPRjz0ou37JPbdOfsuZh5picX5/0s+61Lg5oKbqDHyzHWJwM9iaJ9ThuDHxYRP8zp0z4CyacDs1spr8tVsYpKTxYkOY5Ye4eDbQgVYTj0kqUG8whmCMZIm1ZD4OMg1d8Fyw==
X-YMail-OSG: uoV.n9oVM1lxp3LakqZ_JxzYgcLqTcH2LbGw.iOAoaMcqq7TACkLGMBF6zQymA.
 q8P2mKlAGOLjLOshr_G5Mg6Nr4ASIkQ.41ScEtYvzSBfxQJv2OQJwfD85PeHFjmpwGrPsuMZ67QL
 INHDHNH4JW6ML4BwihSoRVYlMLooTLRcj0uK5wyQzCit8gzyGMH7xW3nR6aoTTuqtAJ2CtcOfxHF
 4hhR7uAh5Nj5CEsrUIOINxjmy1Sx0W6Tqby58pdDlXVUjMZqm2pkPt8N0M6UIi4kxoNEyg6rdxRw
 7sYl54M8T5F6vxST.d0SOhHw8.Wvp7ldOY1HUB8rUc.keTG.BMVxjWnW0ITIscp3U5tPs5EyL4PH
 u.HBhVlT4rKqMmZycCLLWS.ACpDKZNAgXzKfH9fwzkYYowvgxfamkZFfcHPJTT2Y23lqDwbm7rRX
 4A5OQw2WeLAY0MSVAahDKHj5dgPolb9ltnKvXIk0CaImH8xgfNZESeKILW1WnicQ8ABdv48GFZcC
 ZxHR8v3eJqreQBpLCpTSJQ8y3VdrmeMEPESlLwDDpcJdBDu.z8DNsEOhuOEYOjYwggrOBtL2Zme.
 vMx9rZphbnEvtGREpVRVLjj5YhqUGc1dzUx0s6Uqm_7fbRIRTpsA8GPSdvGB7R0j9a5.rrDRYTZn
 jfmxq5z76
Received: from sonic.gate.mail.ne1.yahoo.com by
 sonic303.consmr.mail.ir2.yahoo.com with HTTP; Fri, 14 Jul 2017 21:30:27 +0000
Date: Fri, 14 Jul 2017 21:30:26 +0000 (UTC)
From: Olivier Morand <omorand@yahoo.fr>
To: Wikimedia France Public Mailing List <wikimediafr@lists.wikimedia.org>
Message-ID: <1875202748.906589.1500067826867@mail.yahoo.com>
MIME-Version: 1.0
References: <1875202748.906589.1500067826867.ref@mail.yahoo.com>
X-Mailer: WebService/1.1.10092 YahooMailNeo Mozilla/5.0 (Windows NT 6.3; WOW64;
 rv:54.0) Gecko/20100101 Firefox/54.0
Content-Length: 9571
X-Mailman-Approved-At: Sun, 16 Jul 2017 12:09:41 +0000
Subject: Re: [Wikimediafr]
	=?utf-8?q?missions_du_CA_=28was=3APr=C3=A9paration_?=
	=?utf-8?q?de_l=27AG=29?=
X-BeenThere: wikimediafr@lists.wikimedia.org
X-Mailman-Version: 2.1.18
Precedence: list

etc...


------------------

I have no idea what it means. I have no idea what to do. HELP !


Anthere


_______________________________________________
Listadmins mailing list
Listadmins@lists.wikimedia.org
https://lists.wikimedia.org/mailman/listinfo/listadmins