28 Jan
28 Jan
9:16 a.m.
On January 27, 2022 9:05:50 PM PST, ruin mechanic via sudo-discuss
<sudo-discuss(a)sudoroom.org> wrote:
It appears that the list sets the sender's email address as the Reply-To header.
Here's what I saw from this message:
Reply-To: ruin mechanic <ruinmechanic(a)gmail.com>
--Sean
11:40 a.m.
Yeah, when I reply to this message, it's directed to you. I'm replying all,
which should send it to the whole email list.
Would it make sense to set sudo-discuss as the default? That feels more
natural to me.
*Andrew R Gross, (he/him)*
412.657.5332 - shrad.org <http://www.shrad.org>
On Fri, Jan 28, 2022 at 9:26 AM Sean Greenslade via sudo-discuss <
sudo-discuss(a)sudoroom.org> wrote:
8:12 p.m.
On Fri, Jan 28, 2022 at 11:41 AM Andrew R Gross via sudo-discuss
<sudo-discuss(a)sudoroom.org> wrote:
The list address is the From header, and the person's address is
Reply-To. This is necessary to comply with DMARC. Reply-all should
include both by default, but gmail often obscures the list address
behind the sender's name in misleading ways.
29 Jan
29 Jan
12:59 p.m.
Can you explain what DMARC is and why the reply setup is necessary for it?
I tried to google it but didn't understand how it connects.
*Andrew R Gross, (he/him)*
412.657.5332 - shrad.org <http://www.shrad.org>
On Fri, Jan 28, 2022 at 8:18 PM ruin mechanic <ruinmechanic(a)gmail.com>
wrote:
1:28 p.m.
On Sat, Jan 29, 2022 at 1:01 PM Andrew R Gross <arg5029(a)gmail.com> wrote:
Also, did that message go to the whole channel? Or
just Ruin, Yardena, and Sean?
You are sending emails to "ruin mechanic via sudo-discuss
<sudo-discuss(a)sudoroom.org>" which goes to the whole list, but which
gmail ~helpfully displays as just "ruin" unless you click on it to
show the full address.
DMARC helps servers verify that mail is legit. Messages are signed by
a private key, and the receiver checks it against a public key over
dns. The "from" field has to match the actual sender's domain. When
sudoroom.org sends you mail, it has to say "From: ... sudoroom.org" or
it will fail the test. We can't send mail that says "From: Andrew R
Gross <arg5029(a)gmail.com>" because we don't have the private key for
gmail.com.
11:21 p.m.
New subject: test, and also DMARC
On Sat, Jan 29, 2022 at 12:59:42PM -0800, Andrew R Gross wrote:
Can you explain what DMARC is and why the reply setup
is necessary for it?
I tried to google it but didn't understand how it connects.
There's a very deep rabbit hole to go down when you start discussing all
the various interlinking components of modern email. I'll give the short
version, since this is probably veering pretty far off-topic for the
sudo-discuss@ list.
DMARC is a primarily a method of authenticating a given message to
ensure that it was actually sent by who it purports to be from. One of
the ways it does this is by allowing the owner of a domain name to
specify that emails from that domain must be signed in a specific way
(typically DKIM signatures). It can also require that mail from that
domain comes from an authorized server (via SPF rules).
This is all well and good until a mailing list gets involved. If the
list server were to take a message and just forward it as-is, the
message would no longer align with the SPF record since the list server
is operating under a different domain. The list server also can't
pretend to be the original sender's domain since that would cause the
SPF check to outright fail.
Additionally, mailing lists will usually modify the message, for example
by adding list headers, unsubscribe links, or adding the list address as
the reply-to. This will break some DKIM signatures, and most end users
have no way of affecting how their mail server signs outgoing mails.
Breaking either SPF or DKIM can cause DMARC to fail and thus make any
list recipient's mail server that is set to enforce DMARC restrictions
reject the mail. These rejections go back to the list server, which may
unsubscribe the unlucky recipient through no fault of their own (since
their mail server is correctly rejecting a DMARC failure as the original
sender requested).
Thus the solution is to decouple the mailing list message from the
original domain. This is done by editing the From: header to use the
list address. Thus, recipients of the list message will check the DMARC
restrictions of the list server, which should always pass for valid list
messages (mailing list domains typically use a DMARC policy of "none").
This message modification strategy has its own downsides, but that's a
discussion better suited for the mailop@ mailing list.
--Sean
30 Jan
30 Jan
1:52 a.m.
New subject: test, and also DMARC
I think that one possible solution to reduce confusion is this:
instead of the mail server sending email out like this:
"From: Sean Greenslade via sudo-discuss <sudo-discuss(a)sudoroom.org>"
we should change the name part slightly to put sudo-discuss first:
"From: sudo-discuss Sean Greenslade <sudo-discuss(a)sudoroom.org>"
that way, gmail users will see "sudo-discuss" in the places where Gmail
abbreviates the From description. That's the most important information at
that time.
If they want to know which sender created the email, they can look at the
writing style, wall-of-text, or whatever, and eventually see the signature.
But at least it will reduce confusion
-jake
On Sat, 29 Jan 2022, Sean Greenslade via sudo-discuss wrote:
10:29 p.m.
New subject: test, and also DMARC
Wow, that was a great explanation. Thank you.
My next question is how I should best respond. If I understand correctly,
replying sends the email to just the original sender, but replying all
sends it to the whole discussion list. Is that right?
*Andrew R Gross, (he/him)*
412.657.5332 - shrad.org <http://www.shrad.org>
On Sat, Jan 29, 2022 at 11:21 PM Sean Greenslade <sean(a)seangreenslade.com>
wrote:
31 Jan
31 Jan
9:09 p.m.
New subject: test, and also DMARC
On Sun, Jan 30, 2022 at 10:29:21PM -0800, Andrew R Gross wrote:
Depends on the mailing list, and to some extent the users personal
preferences. I've seen it both ways; some people like being CC'd so it
gets their attention, while others are annoyed by the duplicate messages
from both the sender and the list.
Generally, if it's a closed (must be a subscriber to send) list,
replying only to the list address is preferable. If it's an open list, I
might err on the side of reply-all-ing if I don't know that the original
sender is a subscriber.
Since I don't actually remember if this list is an open one, I kept your
email on CC.
--Sean
1 Feb
1 Feb
10:05 a.m.
New subject: test, and also DMARC
Okay. I'm going to keep replying to all then. If there's a different
etiquette for this list, someone please let me know.
*Andrew R Gross, (he/him)*
412.657.5332 - shrad.org <http://www.shrad.org>
On Mon, Jan 31, 2022 at 9:09 PM Sean Greenslade <sean(a)seangreenslade.com>
wrote:
12:44 p.m.
New subject: test, and also DMARC
I usually reply-all, and I don't worry about it too much because our mailserver
has a function, that's enabled by default, to prevent duplicate messages:
Receive list copies (possible duplicates) (default: NO)
When you are listed explicitly in the To: or Cc: headers of a list message,
you can opt to not receive another copy from the mailing list. Select Yes to
receive copies. Select No to avoid receiving copies from the mailing list
as always, you can Manage Subscription preferences for your delivery, at the
following link:
https://sudoroom.org/lists/postorius/lists/sudo-discuss.sudoroom.org/
if you don't know your password, it's possible that you don't have one yet,
and
you need to pick one to be able to "login" to that page to control your email
settings.
-jake
On Tue, 1 Feb 2022, Andrew R Gross via sudo-discuss wrote:
1149
days inactive
1153
days old
14 comments
5 participants
participants (5)
-
Andrew R Gross -
Jake -
ruin mechanic -
Sean Greenslade -
Yardena Cohen