[Mailman-Users] DMARC issues

Peter Shute pshute at nuw.org.au
Sat Apr 12 11:59:10 CEST 2014

> On 12 Apr 2014, at 11:53 am, "Mark Sapiro" <mark at msapiro.net> wrote:
> Maybe. Yahoo requests and receives reports of rejected mail. This is
> only speculation, but if Yahoo sees that your server is sending what it
> considers to be bogus mail purporting to be From: its domain, it could
> decide to reject all mail from your server.

That's a very disturbing thought, even more so it they're contributing to blocklists that are used elsewhere.

> The list admin can see these values on the list's web admin Bounce
> processing page, but defaults are:
> bounce_score_threshold = 5.0
> bounce_info_stale_after = 7
> bounce_you_are_disabled_warnings = 3 = 7

Thanks for those. Is the last one a typo? Otherwise, what does =3=7 mean?

With these settings, and address will have to bounce on 5 days, with no breaks of 7 days or more before being disabled?

After they're disabled, they get a warning email every bounce_you_are_disabled_warnings_interval days, correct? What's the default for that, please? 

And then after bounce_you_are_disabled_warnings of these, they're actually unsubscribed?

>> Am I right in thinking that if we make these values high enough, we'll see no accounts disabled, and the only side effects will be more bounces and yahoo mail won't get through? Would this be an acceptable solution for a list with only 1000 members and low traffic, assuming we warn the yahoo members to use a different address?
> Just turn off bounce processing for the list. See the FAQ at
> <http://wiki.list.org/x/ggARAQ>.

That should work for us for now, but won't we have a growing load of bounces as time goes by? I was thinking it might be better to get rid of those addresses that are permanently bouncing every message, even if we take longer to do it than before.

> Additional reading at <http://www.dmarc.org/faq.html#s_3>,
> <http://blog.threadable.com/how-threadable-solved-the-dmarc-problem> and
> <http://www.spamresource.com/2014/04/run-email-discussion-list-heres-how-to.html>
> and other articles linked from those.

From the threadable article:
“He recommends that all list administrators immediately stop delivering to Yahoo addresses to limit damage, and encourage members to move to a more friendly provider."

How would not delivering to yahoo addresses help? I thought the problem was with delivering yahoo email to others.

And I'm wondering about asking people to move off yahoo. We might have to do that, but what happens if they go to the trouble of getting a gmail account, and then google starts doing the same thing? They're not going to be happy.

Peter Shute

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