[Mailman-Users] from_is_list Wrap Message: what does that look like?

Mark Sapiro mark at msapiro.net
Wed Jan 11 18:19:17 EST 2017

On 01/11/2017 02:42 PM, Matt Morgan wrote:
> On Wed, Jan 11, 2017 at 2:09 PM, Mark Sapiro <mark at msapiro.net> wrote:
>> The big negative of Munge From is the message's From: header no longer
>> contains the address of the author of the message so the message is no
>> longer strictly compliant with RFCs 822, 2822 and 5322.
> Isn't it also an issue that the message doesn't say who it's from,
> potentially, or how to contact the sender?

That should not be the case. The original From: is always put in
Reply-To: or in some cases Cc: with the intent that a compliant MUAs
'reply' and 'reply all' function will address the reply the same whether
or not the message is Munged. Also, the sender's display name in the
original From: is preserved. In a simple case with no Reply-To: munging,
a message

From: Joe Poster <joe at example.com>

will be sent from the list with

From: Joe Poster via AList <alist at example.net>
Reply-To: Joe Poster <joe at example.com>

> Or, I would guess on any list, someone will often say "contact me for more
> info" with the assumption that their email address is up above. Am I
> misunderstanding Munge From?

Yes. I think so. This is what the code says

>     # MAS: We need to do some things with the original From: if we've munged
>     # it for DMARC mitigation.  We have goals for this process which are
>     # not completely compatible, so we do the best we can.  Our goals are:
>     # 1) as long as the list is not anonymous, the original From: address
>     #    should be obviously exposed, i.e. not just in a header that MUAs
>     #    don't display.
>     # 2) the original From: address should not be in a comment or display
>     #    name in the new From: because it is claimed that multiple domains
>     #    in any fields in From: are indicative of spamminess.  This means
>     #    it should be in Reply-To: or Cc:.
>     # 3) the behavior of an MUA doing a 'reply' or 'reply all' should be
>     #    consistent regardless of whether or not the From: is munged.
>     # Goal 3) implies sometimes the original From: should be in Reply-To:
>     # and sometimes in Cc:, and even so, this goal won't be achieved in
>     # all cases with all MUAs.  In cases of conflict, the above ordering of
>     # goals is priority order.

We think all Mailman versions 2.1.19 and later do a good job of meeting
those goals.

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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