[ClusterLabs] @ maillist Admins - DMARC (yahoo)

[Andrei Borzenkov]

On Mon, Jul 12, 2021 at 5:50 PM <kgaillot at redhat.com> wrote:
>
> On Sat, 2021-07-10 at 12:34 +0100, lejeczek wrote:
> > Hi Admins(of this mailing list)
> >
> > Could you please fix in DMARC(s) so those of us who are on
> > Yahoo would be able to receive own emails/thread.
> >
> > many thanks, L.
>
> I suppose we should do something, since this is likely to be more of an
> issue as time goes on. Unfortunately, it's not as simple as flipping a
> switch. These are the two reasonable choices:
>

The problem is, both are incomplete.

>
> (1) Change the "From" on list messages so that they appear to be from
> the list, rather than the poster. For example, your posts would show up
> as "From: lejeczek via ClusterLabs Users <users at clusterlabs.org>"
> rather than "From: lejeczek <peljasz at yahoo.co.uk>". This is less
> intrusive but makes it more difficult to reply directly to the sender,
> add the sender to an address book, etc.
>

This will pass SPF but fail DKIM

>
> (2) Stop adding [ClusterLabs] to subject lines, setting ReplyTo: to the
> list instead of original author, and adding the list signature. This is
> more standards-compliant, since the List-* headers can still be used
> for filtering, unsubscribing, and replying to the list, but not all
> mail clients make those easy to use.
>

This will pass DKIM but fail SPF.

I do not know how many domains implement only SPF, only DKIM or both.

>
> Anyone have preferences for one over the other?
>
> (Less reasonable options include wrapping every post in MIME, and
> disallowing users from DMARC domains to post to the list.)

Well, enabling ARC in addition to either of the options may somehow
mitigate them. It depends on *recipient* domain support though. Also I
am not sure whether Mailman 2.x supports it.

>From a personal perspective, I already filter by list ids and
[ClusterLabs] just wastes screen real estate. But I remember somewhat
heated responses when openSUSE changed list software and dropped
prefixes - apparently quite some users were using single mailbox and
relied on prefixes to prioritize message reading.