Re: [tlug] DMARC Test

[Bernie Innocenti <bernie@??>]

On 5/30/26 18:17, Stephen J. Turnbull wrote:
>   > Do you see my From email as bernie@?? or something else?
>
> I see it as bernie@??.  I don't think TLUG will alter your
> from, though, so you may see your posts rejected.

Ah! I had accidentally replied only to you :-)

No wonder I couldn't find this message in the mailing list's archive!

But I found a previous message, and the From had been munged to "bernie@??".


>   > I checked how to implement ARC with Postfix (my long time MTA), but
>   > the only option I found is OpenARC, which seems badly maintained
>   > and not even packaged in Debian & Ubuntu.
>
> It doesn't help mail you originate to implement ARC.  The idea of ARC
> is to check your mail for SPF and DKIM, put the results in an
> ARC-Authorization-Results header, and digitally sign with the mailing
> list's private key.  If you are doing DKIM correctly (signing at the
> edge of your administrative domain aka boundary MTA, which for small
> organizations is often the only MTA), ARC is redundant.  So the
> mailing list or other forwarding agent or proxy has to do it.  If
> you're running such an agent or proxy, then it would help.

I see. Mailman 3 would support ARC:

https://docs.mailman3.org/projects/mailman/en/latest/src/mailman/handlers/docs/arc_sign.html

...but we're still running Mailman 2.1.29.

And yes, I'm aware that MM3 is a complete rewrite, so it's not a trivial 
migration. Is the host new enough to run the latest MM3?


>   > So I'd rather not set it up until large email providers start
>   > actively blocking my posts to mailing-lists.
>
> Oh, the email providers won't *block* your posts.  They'll *reject*
> them, and *other* people will show up at mailing lists as
> undeliverable, and those *other* people will have their subscriptions
> disabled or cancelled.  That's what's so horrible about p=reject.
> You're fine, it hurts other people.
Haha, you're right ;-)

This slightly outdated article shows that in 2024 senders were almost 
evenly split between p=quarantine and p=reject:

https://www.emailonacid.com/blog/article/email-deliverability/why-strong-dmarc-policy/

We can only assume that the percentage of p=reject will keep on growing, 
as the end goal is to eventually get to 100%.

--
_ // Bernie Innocenti
\X/  https://codewiz.org/