[Mailman-Users] DMARC issues

Mark Sapiro mark at msapiro.net
Fri Apr 11 02:25:16 CEST 2014

On 04/10/2014 07:25 AM, Joseph Brennan wrote:
> They're breaking RFC 822 / 5322.
>  The "From:" field specifies the author(s) of the message,
>   that is, the mailbox(es) of the person(s) or system(s) responsible
>   for the writing of the message.  [...]
>   In all cases, the "From:" field SHOULD NOT contain any mailbox that
>   does not belong to the author(s) of the message.
> I don't think we should compound that by changing the From line.

Several others have made relevant replies while I was on the plane to
Montreal, registering for PyCon, attending the opening reception ...

Anyway, I wanted to say I agree completely with the above even though
the DMARC community does not. That's why I implemented the option in
2.1.16 to wrap the original post as a message/rfc822 part attached to a
new message from the list.

Unfortunately, when I actually turned this on in response to Yahoo's
change in DMARC policy, I got complaints from users of Apple iOS iThings
that their mail clients do not deal well with this message, so I
reluctantly went the non-compliant mung the From: way.

Yesterday I wrote a brief FAQ on this which is at

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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