[MlMt] MailMate Mailing List Address Munging Question..

[Bill Cole]

[putting on mail admin hat]

On 27 Aug 2019, at 13:00, Billy Youdelman wrote:

> I've noticed an annoying trend in how the source addresses of messages 
> posted to some mailing lists (most notable Apple's) are being 
> modified.
>
> For instance, Denis Ricard <d.ricard at me.com> posts a note here, but it 
> shows up as being from
>
> Denis Ricard via mailmate <mailmate at lists.freron.com>

Yes. This is an unfortunately necessary tactic to protect a mailing list 
from the negative side-effects of the "DMARC" mechanism of combatting 
email forgery. It is often done (as with this list, apparently) only for 
senders whose email provider has publishes an active DMARC policy of 
"quarantine" or "reject".

The reason for that is because many mailing lists modify message bodies 
and/or headers which are usually signed by the DKIM mechanism that DMARC 
uses for message authentication. This breaks the message signature. When 
the DMARC policy for the domain of the From header is "quarantine" or 
"reject", a broken signature can result in mail being rejected, 
quarantined, or shunted to a "spam folder," which can ultimately lead to 
mailing lists being seen as spam by receiving sites or (in the case of 
outright rejections) having subscribers at DMARC-honoring sites being 
unsubscribed due to excessive bounces.

> I wouldn't know where Denis actually is had he not CC'd himself.

That MAY be a part of the munging being done by Mailman, the mailing 
list software that handles this list and does the munging. Moving the 
original From address to the Cc or to Reply-To header is one option in 
Mailman's munging config.

> Is this going to be how addressing will now be handled here?

I can't know for sure, but the *selective* munging strategy or worse 
(e.g. everyone switched to digest mode, effectively, with one-message 
digests) is going to become pervasive for lists that do things like add 
listname/topic tags or add list footers, both of which this list does. I 
would not expect it to be switched back.

> If so, please count me as one vote to keep things as they were.  I 
> really don't need any more protection from spam (having been using 
> email since well before junk mail existed, I couldn't possibly get any 
> more, heh),

It's entirely not about spam reduction. It's about maintaining the 
viability of traditional discussion mailing lists in the face of a 
tactic pushed mainly by large service providers who offer both mailboxes 
and their own captive discussion group alternatives to traditional 
discussion mailing lists.


> and I'd also like to retain the option of sending a reply to just an 
> author, directly.

Because the munging appears to include moving the original From address 
to a Cc header, you should retain that option.


-- 
Bill Cole
bill at scconsult.com or billcole at apache.org
(AKA @grumpybozo and many *@billmail.scconsult.com addresses)
Not Currently Available For Hire