Re: [Evolution] [Fwd: You have been unsubscribed from the evolution-list mailing list]

[Patrick O'Callaghan <poc usb ve>]

On Sat, 2016-07-30 at 22:54 +0200, Ángel González wrote:
> On 2016-07-29 at 15:24 +0100, Patrick O'Callaghan wrote:
> > It's tempting to think so, but there are also users with pacbell and
> > bellsouth addresses who have similar problems. I note that both of them
> > route their mail through prodigy.net, if that means anything.
> >
> > poc
>
> Apparently, prodigy.net email service is actually provided by yahoo;
> https://en.wikipedia.org/wiki/Prodigy_(online_service)#A_public_company
>
>
> So it is really just yahoo having problems with emails from their own
> customers that passed through a mailing list.

OK, good sleuthing :-)

> I got the hint by the error message given by the prodigy mailserver
> when attempting to spoof a yahoo From:
> > <<< 554 5.7.9 Message not accepted for policy reasons.  See 
> > https://help.yahoo.com/kb/postmaster/SLN7253.html
> > 554 5.0.0 Service unavailable
>
>
> I'm quite sure it is related to their DMARC reject policy (perhaps even
> marked internally).

Looks like it, however I don't understand why it's only affecting a
very small number of users, and only occasionally.

> It asserts that yahoo.com emails will only ever come from yahoo
> servers, and non-complaint emails shall be *rejected*. This makes
> complete sense for eg. paypal.com but for a free mail provider like
> yahoo imho such policy is broken. Precisely because it completely
> breaks mailing lists:
> https://en.wikipedia.org/wiki/DMARC#Mailing_lists
>
>
> Also, it should be noted that other providers may also be taking that
> into account. For instance gmail accepts those DMARC-failing messages,
> but they are sent to the Spam folder.

My address (@usb.ve) is a Google Apps for Education account. I have
another Gmail address on several Mailman lists. None of them has ever
been affected by this.

> There are a few options in recent mailman versions for handling this,
> although none seems specially appealing:
> https://wiki.list.org/DEV/DMARC

I'll consider passing this on to the Gnome admins but it's seems likely
they would already know about it.

poc