[Mailman-Users] Bounce Processing

Mark Sapiro mark at msapiro.net
Thu Apr 21 00:14:07 EDT 2016

Mark Sapiro wrote:

> There are two separate issues here. He cannot send to Mailman and
> Mailman can't send to him. The first causes him to get the rejections as
> above and the other causes Mailman's bounce processing to unsubscribe him.

I partially misinterpreted the situation. I have received an off-list
message from the proprietor of the subject Mailman hosting service with
whom we have an excellent relationship (and he has now posted to the list).

He has clarified a few things. The only messages that are bouncing are
the problem user's posts from the list back to him. He receives other
user's posts OK, and his posts are delivered to all the list members and
only the list post to him is bounced.

It appears to me from what I now know and see that this is a pseudo
DMARC issue. The user's ISP, pphosted.com is saying that mail which has
a From: header domain which is "our domain" and To: a user in "our
domain" must come from our servers to be accepted. I.e., they don't
publish a DMARC policy, but when checking incoming mail on their own
servers they pretend they publish p=reject.

This is not SPF per se. SPF deals only with the domain of the envelope
sender, not the From: header.

Since pphosted.com doesn't publish a DMARC policy, you can't work around
this by setting dmarc_moderation_action. You can set from_is_list to
Munge From or Wrap Message and I'm sure that will allow these posts to
go through, but that is a heavy hammer which affects all list posts.

Perhaps with this info, the user can talk again to pphosted and get an
intelligent response. This does not appear in any way to be an issue
with emwd.com's configuration.

Mark Sapiro <mark at msapiro.net>        The highway is for gamblers,
San Francisco Bay Area, California    better use your sense - B. Dylan

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