offtopic: rant about thoughtless enabling DMARC checks [was: Re: Bounces?]

[Juri Haberland]

On 09/02/2019 10:44, Aki Tuomi via dovecot wrote:
> For some reason mailman failed to "munge from" for senders with dmarc policy ;(
> 
> It's now configured to always munge to avoid this again.

I'd say, let Mailman throw all people off the list that have enabled DMARC
checking without using exceptions for the lists they are on. It's a known
fact that DMARC does not cope well with mailing lists. Blindly enabling
DMARC checks without thinking about the consequences for themselves should
not be the problem of other well behaving participants.

Most people use OpenDMARC and there are patches to mark certain hosts as
mailing lists senders, so it is possible.

And everyone using p=reject should think about it as well - as I said,
DMARC does not play well with mailing lists, so setting p=reject on a
domain used to participate on mailing lists is not wise, to say the least.
You should not follow Yahoo and AOL - you know, why they did it, don't you?

And Aki, please go back to "munge only if needed" - munging all messages
leads to a really bad "user experience".

Thanks.


Back to lurking,
  Juri