Re: Mailing list membership.

[Kazunori ANDO <[e-mail]>]

Hi, folks

I made note about these conflicts. FYI.

https://www.facebook.com/notes/%E5%AE%89%E8%97%A4-%E4%B8%80%E6%86%B2/memo-about-some-conflicts-between-mailing-lists-and-dmarc/1332635393468971
-- 
Kazunori ANDO / [e-mail]

On 2017/03/01 13:49, Theodore Ts'o wrote:
> On Tue, Feb 28, 2017 at 05:29:24PM -0300, willi uebelherr wrote:
>>
>> related to the problem, what Khaled explained, what is your proposal?
>>
>> What are your "compatible with internet mailing lists" mail systems?
>
> RFC 2821, Simple Mail Transfer Protocol, section 3.10.2
>
>    "To expand a list, the recipient mailer replaces the
>    pseudo-mailbox address in the envelope with all of the expanded
>    addresses.  The return address in the envelope is changed so that all
>    error messages generated by the final deliveries will be returned to
>    a list administrator, not to the message originator, who generally
>    has no control over the contents of the list and will typically find
>    error messages annoying."
>
> This is the SMTP Envelope From field.  The FROM field is not changed,
> but the SMTP return address is changed, so that bounces go to the
> mailing list administrator as opposed to the person who sends mail to
> the mailing list.
>
> Unfortunately, if you are using a system whose domain requests that
> all recipients enforce DMARC alignment, this specifically instructs
> recipients to bounce mail if the SMTP Envelope return address doesn't
> match the FROM field in the header.  This means that they won't see
> mailing list mail as defined by the IETF Standards Track RFC 2821,
> which specifically says that is acceptable (and in fact a good thing)
> to change the SMTP envelope return address so that bounces (caused by
> people changing where they work, etc.) go to an administrator who can
> deal with them.  But if the mailing list administrators gets too may
> bounces, and it's because the sending domain is requesting that mail
> be bounced, the only thing they can do is to unsubscribe the sender or
> the recipient.
>
> Hence mailing list systems that enforce DMARC, or request DMARC
> processing, are fundamentally incompatible with mailing lists as
> defined by section 3.10.2 of RFC 2821.
>
> If you want to participate in such mailing list, one of the best ways
> is to change to a mailing list system that doesn't do DMARC.
>
> Best regards,
>
> 						- Ted
>
>