Re: [dmarc-ietf] Is there any recommendation to send DMARC message-specific failure reports FROM:<> ?

Hello John,

at SMTP level the server communicates EHLO mail.modernwebsite.pl and  
ENVFROM:<>.  There is no TXT record for mail.modernwebsite.pl so SPF  
fails and cannot align.

The email itself contains “From: MAILER-DAEMON@modernwebsite.pl (Mail  
Delivery System)” without DKIM signature. ⇒ DMARC validation fails.

You can give it a try and send yourself a message to  
“postmaster@modernwebsite.pl”, the answer will be
   <template@modernwebsite.pl> (expanded from <postmaster@modernwebsite.pl>):
     unknown user: "template"

Unfortunately I had another loop back in September 2018.  I do not  
remember the details.  Given that this can happen again to somebody  
else, it is better to have recommendation sending the message-specific  
reports with FROM:<> or NOTIFY=NEVER, or at least some text  
elaborating on the attack.

Regards
   Дилян

----- Message from John Levine <johnl@taugh.com> ---------
    Date: 26 May 2019 10:44:39 -0400
    From: John Levine <johnl@taugh.com>
Subject: Re: [dmarc-ietf] Is there any recommendation to send DMARC  
message-specific failure reports FROM:<> ?
      To: dmarc@ietf.org
      Cc: Dilyan.Palauzov@aegee.org

> In article  
> <20190526050958.Horde.6VaAxRZKGLqyeJ4Uov0vrXR@webmail.aegee.org> you  
> write:
>> Hello John,
>>
>> in case of modernwebsite.pl:
>>
>> DNS TXT _dmarc.modernwebsite.pl is "v=DMARC1; p=reject; pct=100;
>> rua=mailto:postmaster@modernwebsite.pl;
>> ruf=mailto:postmaster@modernwebsite.pl; aspf=s;adkim=s;"
>>
>> Emails to postmaster@modernwebsite.pl are answered with “Undelivered
>> Mail Returned to Sender”.  The answers do not align to the DMARC
>> policy reject, so a new message-specific failure repot is sent.
>
> Just out of curiosity, where do the reports come from?  I see their
> SPF record says "mx a".
>
> _______________________________________________
> dmarc mailing list
> dmarc@ietf.org
> https://www.ietf.org/mailman/listinfo/dmarc

----- End message from John Levine <johnl@taugh.com> -----