[Linux-31] problème avec dmark?

[jdd]

Bonjour,

J'ai un souci comme administrateur de linux-31 (entre autres), certains 
utilisateurs sont désabonnés, et je recois un message de mailman (voir 
ci-dessous).

mais je ne comprends pas exactement ce qui se passe. Ca vient de yahoo 
ou de gmail?

quelle est la manière la moins invasive de corriger ce problème?

merci
jdd


Reporting-MTA: dns; revival.culte.org
X-Postfix-Queue-ID: 24550409BD
X-Postfix-Sender: rfc822; linux-31-bounces at culte.org
Arrival-Date: Fri, 17 Mar 2017 09:04:37 +0100 (CET)

Final-Recipient: rfc822; XXXX at gmail.com
Original-Recipient: rfc822;XXXX at gmail.com
Action: failed
Status: 5.7.1
Remote-MTA: dns; gmail-smtp-in.l.google.com
Diagnostic-Code: smtp; 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. t5si2165200wme.37 - gsmtp

Final-Recipient: rfc822; yyyyy at yahoo.com
Original-Recipient: rfc822;yyyyy at yahoo.com
Action: failed
Status: 5.7.9
Remote-MTA: dns; mta7.am0.yahoodns.net
Diagnostic-Code: smtp; 554 5.7.9 Message not accepted for policy 
reasons.  See
     https://help.yahoo.com/kb/postmaster/SLN7253.html