Why do so many dovecot list mails fail dmarc?

[@lbutlr]

On 2021 Aug 13, at 11:11, dovecot at ptld.com wrote:
> 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;

This seems overly restrictive for a mailing list, I think, and I do not know why Reply-to and From are both listed twice. However, it is not where the failure is.

Authentication-Results: smtp.ptld.com;
     dkim=fail reason="signature verification failed" (1024-bit key; secure) header.d=protonmail.ch
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=

That signature is from smtp.ptld.com and it is that signature that is failing, I believe.


-- 
Hi, I'm Gary Cooper, but not the Gary Cooper that's dead.