dovecot mailing list (this mailing list), DKIM, SPF and DMARC

[Dave McGuire]

On 10/11/22 07:42, hi at zakaria.website wrote:
> Another update yet with a solution.
> 
> I found the causing issue with DKIM and DMARC failure when a signed 
> email pass through mailing list such as dovecot as I expected, it has 
> nothing to do with the mailing list but it's to do with DKIM signing 
> headers set. It's due to one of or several headers in the DKIM signing 
> set, getting added or modified after signing at dovecot end.
> 
> Anyhow, here is the DKIM signing headers set in this mailing list, that 
> it should work and it will prevent the batch of DMARC emails and bad 
> signature from happening again.
> 
> from:from:reply-to:date:date:message-id:message-id:to:to:cc:
>       mime-version:mime-version:content-type:content-type:
>       in-reply-to:in-reply-to:references:references
   Please forgive me for jumping in, but I just noticed this.  I (like 
many others) have issues with mailing lists and the flurry of DMARC 
emails after posting.  I'm using OpenDKIM.  There's a lot of material 
out there about proper configuration of DKIM, but nothing really 
definitive, with lots of "it depends on your requirements" type of 
noncommittal crap.  Email use cases don't differ THAT much.

   So does what you said above mean that you've come up with a working 
configuration to address the issue of mailing lists causing DKIM to barf 
due to header modifications?  If so, can you tell me more about 
specifically what you're doing, like which headers you're signing and 
how?  I've been at my wits' end with this for some time; DKIM (and SPF 
etc etc) seem to be really quite awful overall.

             Thanks,
             -Dave

-- 
Dave McGuire, AK4HZ
New Kensington, PA