[Users] DKIM Signature issues [Was: List server: bad DKIM?]

[Pierre Fortin]

On Fri, 16 Feb 2018 17:54:35 -0500 I wrote:

>Hi,
>
>Did something change on the list server recently?
>
>With the list more active lately, I've noticed that I'm seeing replies
>to messages I haven't seen. Tracked this down to my MTA (luxsci.com)
>deleting messages with DKIM issues. Rather than delete, I've changed the
>MTA action to modify the message by adding "DKIM" in the Subject and it's
>now passing more list messages with DKIM in the subject. Strangely,
>some messages pass the DKIM test while others don't...

Changed: removed DKIM from subject; now, it adds a custom header which CM
uses to color messages with bad DKIM signatures.

>Is the list server's DKIM failing?

Nope; problem is mainly GMail; it generates bad DKIM signatures.  Reported
the following to Google at https://productforums.google.com/forum/#!forum/gmail

   ------------------
   I receive emails from a list server (lists.claws-mail.org). I've
   noticed that recently, some messages are replies to messages I've
   never seen. Finally tracked this down to DKIM signature failures in
   emails originating from:  *@gmail.com, *@invalid.tld(passes through
   gmail.com(d=1e100.net;) servers)  There may be others; but these are
   the most obvious so far...

   PS The "required" categories are useless for this report because I'm
   reporting DKIM failures on messages FROM GMail.
   -------------------

Removed GDPR <removed-gdpr at example.com>:  your messages contain Google DKIM
Signatures; does this seem right to you?

Steve Litt <slitt at troubleshooters.com>:  Your DKIM Signature is not
affected by Google; but for some reason, it is being flagged with:
  DKIM_SIGNED,T_DKIM_INVALID,URIBL_BLOCKED
so my MTA was discarding them.

HTH
Pierre