Why do so many dovecot list mails fail dmarc?

Fri Aug 13 20:11:58 EEST 2021

Im trying to get my head around this problem that too many valid emails 
from the mailing list fail dmarc. Why when other mailing list don't seem 
to have the same problem? I see today it says "signature verification 
failed", but why? Is there a problem with protonmail's dkim key? Is the 
dovecot list altering the message body? Is something wrong on my 
server's end?

The example today was an email from @protonmail.ch, and the headers 
were:

   Return-Path: <dovecot-bounces at dovecot.org>
   Delivered-To: dovecot at ptld.com
   Received: from smtp.ptld.com
       by host.ptld.com with LMTP
       id +SjBLQqiFmFSbgIAjbxwTg
       (envelope-from <dovecot-bounces at dovecot.org>)
       for <dovecot at ptld.com>; Fri, 13 Aug 2021 12:47:06 -0400
   Received: from talvi.dovecot.org (talvi.dovecot.org [94.237.25.159])
       by smtp.ptld.com (Postfix) with ESMTPS id 4GmTx61z3fz4l3g2
       for <dovecot at ptld.com>; Fri, 13 Aug 2021 12:47:06 -0400 (EDT)
   Authentication-Results: smtp.ptld.com; dmarc=fail (p=quarantine 
dis=none) header.from=protonmail.ch
   Authentication-Results: smtp.ptld.com; spf=pass 
smtp.mailfrom=dovecot.org
   Authentication-Results: smtp.ptld.com;
       dkim=fail reason="signature verification failed" (1024-bit key; 
secure) header.d=protonmail.ch header.i=@protonmail.ch 
header.a=rsa-sha256 header.s=protonmail header.b=ivRoCAz3
   Received: from talvi.dovecot.org (localhost.localdomain [127.0.0.1])
       by talvi.dovecot.org (Postfix) with ESMTP id 3862D32297F;
       Fri, 13 Aug 2021 19:46:41 +0300 (EEST)
   X-Original-To: dovecot at dovecot.org
   Delivered-To: dovecot at dovecot.org
   Received: from mail-41113.protonmail.ch (mail-41113.protonmail.ch
       [185.70.41.113])
       by talvi.dovecot.org (Postfix) with ESMTPS id 07C532E9ADB
       for <dovecot at dovecot.org>; Fri, 13 Aug 2021 19:46:37 +0300 (EEST)
   Date: Fri, 13 Aug 2021 16:46:34 +0000
   DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=protonmail.ch;
       s=protonmail; t=1628873196;
       bh=HCYF6+sDiqNN6f9T2srf/HEjnr5eJacuoNxBWXk1XJA=;
       h=Date:To:From:Cc:Reply-To:Subject:In-Reply-To:References:From;

b=ivRoCAz3tXqh7Rk7Orxq6sdNGdIZ8eir4AX6OGxorOOza+XFOLQfBBIp4LfFEFV0y
       hV6b8z8gLmkZaEquwTyh+/Hx3lfpxts6Jvh1zpdL7YvahS2kOjSt0XikXulVgwvvxk
       BNmFxlLWwyVETRpgm5qsQHsNDjYb8HuYID4r1AXM=
   To: Aki Tuomi <aki.tuomi at open-xchange.com>
   From: Laura Smith <n5d9xq3ti233xiyif2vp at protonmail.ch>
   Subject: Re: Undefined symbols (macOS Big Sur Intel) during compiling, 
update
   Message-ID: 
<tQIPhn9Wc9ZCxjWv-REC0bXuE3RgBI1H69xIL0TOnDj-kWvhZXEF7ZR6BevaNCeu8AG9Ypvd7gsnbMEZFAAIkvGmNM3y3UealzoYw9HZSCg=@protonmail.ch>
   In-Reply-To: 
<180775367.20741.1628870488641 at appsuite-dev-gw1.open-xchange.com>
   References: 
<CH2PR06MB6453C343867ECBFD79B73853BCF19 at CH2PR06MB6453.namprd06.prod.outlook.com>

<CH2PR06MB6453D734B09C7D6D2D807787BCFA9 at CH2PR06MB6453.namprd06.prod.outlook.com>
       <180775367.20741.1628870488641 at appsuite-dev-gw1.open-xchange.com>
   MIME-Version: 1.0
   Content-Type: text/plain; charset=utf-8
   Content-Transfer-Encoding: quoted-printable
   X-Spam-Status: No, score=-1.2 required=10.0 
tests=ALL_TRUSTED,DKIM_SIGNED,
       DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_FROM 
shortcircuit=no
       autolearn=disabled version=3.4.4
   X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on
       mailout.protonmail.ch
   ARC-Seal: i=1; s=arc; d=dovecot.org; t=1628873197; a=rsa-sha256; 
cv=none;

b=nuVCke6mta+nYIMyYvb2qRkTUyHSfKXEpp2vTds/ioq0kV4fyIL9oEON09yOoYcrQwci6D

/EBrkZQI6nBjz592m7oslCjeNTcprIJr5QqLY6mJwW7mu+tp4rSEppIyD+r+9dbICExfFO

p3j43c/m0J2acYc5pzZyJM7gLx/RBj2GURAUrP0JaX+y7moB/XQNPIJir2rE/jjNwojKCX

keLRjlzOn7N4dLZxnKHgevDu6tH6gb0OzLPJO7W2IloMxdLZ/ab0PPZOj/M+BaYqnfa1Hs
       T4EvKhSwDjLyhjUQh7QTkmYm/FryVnIxEawEM+huOW9djJe7pIijuNFTqOR4Xg==
   ARC-Authentication-Results: i=1; talvi.dovecot.org;
       dkim=pass header.d=protonmail.ch header.s=protonmail 
header.b=ivRoCAz3;
       spf=pass (talvi.dovecot.org: domain of 
n5d9xq3ti233xiyif2vp at protonmail.ch
       designates 185.70.41.113 as permitted sender)
       smtp.mailfrom=n5d9xq3ti233xiyif2vp at protonmail.ch
   ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; 
d=dovecot.org;
       s=arc; t=1628873197; 
h=from:from:reply-to:reply-to:subject:subject:date:date:
       message-id:message-id:to:to:cc:cc:mime-version:mime-version:
       content-type:content-type:
       content-transfer-encoding:content-transfer-encoding:
       in-reply-to:in-reply-to:references:references:dkim-signature;
       bh=HCYF6+sDiqNN6f9T2srf/HEjnr5eJacuoNxBWXk1XJA=;

b=EYR3Jyq5jrpho8glpLHD60ehlmLaGqrfdZepsfTTJtkjb0AkScBiUB0JX5hGbeyQCdeFvF

zr0g/tfST7KEANMdZ0GK+rmwwSZC7LuKzszXWP+Pi5kBxsDPPU4BUivUkP3abCnGIixXfq

LrEe+/bDrbMkM01wO8sJ0mZccYwURDMTJc7gFjcdSye+3FfKPZAvT9OG2aD2yQhtIVwpbv

+Hg7P5v5Et/muT1E8NHZRBGOPhv4OZ/A2TcOLpafXejddNj2pRtVo8NlFzzT2PBn+KV49M
       nhI4ZDGk43l66nud7wMGDNdUcqYQl6CBQww+kC4ewfNbTy5D27wQwFzpVWGfFQ==
   Cc: "dovecot at dovecot.org" <dovecot at dovecot.org>, Beosdoc 
<beosdoc at hotmail.com>
   X-BeenThere: dovecot at dovecot.org
   X-Mailman-Version: 2.1.15
   Precedence: list
   List-Id: Dovecot Mailing List <dovecot.dovecot.org>
   List-Unsubscribe: <https://dovecot.org/mailman/options/dovecot>,
       <mailto:dovecot-request at dovecot.org?subject=unsubscribe>
   List-Archive: <https://dovecot.org/pipermail/dovecot/>
   List-Post: <mailto:dovecot at dovecot.org>
   List-Help: <mailto:dovecot-request at dovecot.org?subject=help>
   List-Subscribe: <https://dovecot.org/mailman/listinfo/dovecot>,
       <mailto:dovecot-request at dovecot.org?subject=subscribe>
   Reply-To: Laura Smith <n5d9xq3ti233xiyif2vp at protonmail.ch>
   Errors-To: dovecot-bounces at dovecot.org
   Sender: "dovecot" <dovecot-bounces at dovecot.org>