In a list I administer, the From line in an incoming email shows [Poster's Name] via [List Name] <address for posting a reply> . I use Outlook as my client, but at least some other clients behave similarly. However, I have at least one subscriber who uses Mozilla's Thunderbird as his client, and periodically the format changes to something else, most recently to just [List Name <address for posting a reply> . I suspect this occurs from some combination of the way Thunderbird parses the header and the way it populates some kind of address book that makes autofill work, but I'm not sure. Is this a known problem? Is there an easy fix that will be stable? In the past, putting an association in his address book and removing others worked, but it didn't hold and he is frustrated.
On 7/2/25 17:21, Steve Brown via Mailman-users wrote:
In a list I administer, the From line in an incoming email shows [Poster's Name] via [List Name] <address for posting a reply> . I use Outlook as my client, but at least some other clients behave similarly. However, I have at least one subscriber who uses Mozilla's Thunderbird as his client, and periodically the format changes to something else, most recently to just [List Name <address for posting a reply> . I suspect this occurs from some combination of the way Thunderbird parses the header and the way it populates some kind of address book that makes autofill work, but I'm not sure. Is this a known problem? Is there an easy fix that will be stable? In the past, putting an association in his address book and removing others worked, but it didn't hold and he is frustrated.
This From: is the result of DMARC mitigations. The actual From: header in the email is
From: [Poster's Name] via [List Name] <address for posting a reply>
where [Poster's Name] is the first non-empty value from
- the display name in the original From:
- tne display name in the posters member record
- the poster's email address with the domain replaced with
---
How this header is rendered by any particular mail client (MUA) is up to that MUA and not something you can control.
Note however that I use T-bird as my MUA and T-bird displays the From: in your mail from the list as
From Steve Brown via Mailman-users <mailman-users@mailman3.org>
Also, Mailman puts your original From: in a Reply-To: which T-bird displays as
Reply-To Steve Brown <drstephenlbrown@gmail.com>
Depending on your list's settings, the original From: might be in Cc: rather than Reply-To:
And, if the T-bird user really needs to see the poster's name and it's not in any displayed headers, they can always view the source of the message and see the From: there.
-- Mark Sapiro <mark@msapiro.net> The highway is for gamblers, San Francisco Bay Area, California better use your sense - B. Dylan
Thanks, Mark. As usual, your reply was rapid and helpful. I infer that you don't see the instability that my subscriber does. Do (can?) email providers passing the posts to the subscriber alter the headers in ways that might lead to that unstable behavior? Or can it occur because of the way T-bird tries to help the user associate display names with email addresses--autofill and address book automation? Do you have those kind of features turned off in your T-bird? Or is it more likely that the subscriber makes some mistakes that get interpreted as needing a change in From displays? Because only one of my subscribers is complaining regularly, it's not very important for me to do anything, but I'm still curious about the origin of this behavior.
On 7/2/25 19:50, Steve Brown via Mailman-users wrote:
Thanks, Mark. As usual, your reply was rapid and helpful. I infer that you don't see the instability that my subscriber does.
I'm pretty sure I don't, but I'm not completely certain I would notice.
Do (can?) email providers passing the posts to the subscriber alter the headers in ways that might lead to that unstable behavior?
It is possible, but I don't think likely that the final mail delivery agent would do this. It's also almost certain that no intermediate MTA is doing it.
Or can it occur because of the way T-bird tries to help the user associate display names with email addresses--autofill and address book automation?
That seems unlikely since those things would be tied to the email address which is always the same list posting address.
Do you have those kind of features turned off in your T-bird? Or is it more likely that the subscriber makes some mistakes that get interpreted as needing a change in From displays? Because only one of my subscribers is complaining regularly, it's not very important for me to do anything, but I'm still curious about the origin of this behavior.
I don't think I have any non-default settings in my T-bird, and I do have address book entries for various lists and I don't see T-bird showing messages From the display names in my address book.
I am curious as to what the complaint is. Does the user feel that something important is missing or is the concern just the inconsistency?
Also, is there any correlation between the inconsistent behavior and what the poster's name is?
-- Mark Sapiro <mark@msapiro.net> The highway is for gamblers, San Francisco Bay Area, California better use your sense - B. Dylan
I may include more info than you really want to know. Here is the gist of the complaint:
"For a while now, my e-mail for this list (but not other lists) just shows "To RADG" from "RADG" with a "CC" showing the actual sender's address. That becomes a PITA when I need to find a post by a particular person, because the e-mail list does not show the CCs in the list, so I need to open each one to see who actually sent it."
This subscriber is not very savvy about email, and doesn't seem to understand fully when I tell him how it works, so if I start talking about headers, that's a PITA, too. He claims:
"RADG is the only list that is afflicted by this, out of 21 that include groups.io, yahoo, google, Lyris, and probably a few I don't recall."
Because some other members, including me, have had problems with unexpected entries in both From and To lines, I suspect that Mailman 3 does the DMARC enough differently than other lists and forums to cause conflicts with the way the MUAs try to help the user autocomplete an address. Most of those problems go away if they put an association of RADG (Risk Analysis Discussion Group) with radg@lists.radg.us in their address book. We chose the "use your own URL" option. The actual server address is deu.mailmanlists.eu; I don't know whether their customization of the MM3 installation might cause some of the problem.
My understanding is that all of the recent posts are missing the poster's name, after behaving as expected for some time. Something must have changed, but what is baffling me. If you have any further ideas, fine, but don't waste a lot of time on this.
Steve
Steve Brown via Mailman-users writes:
"For a while now, my e-mail for this list (but not other lists) just shows "To RADG" from "RADG" with a "CC" showing the actual sender's address.
It's very difficult to figure out what's going on with such an abbreviated description of what he's seeing.
It may be possible to get better results with alterative settings on the list.
In the settings for RADG, under "Alter Messages", what are the settings for "First strip Reply-To", "Reply goes to list", and "Explicit reply-to address"?
Under "DMARC mitigations", what are the settings for "DMARC mitigation action" and "DMARC mitigate unconditionally"?
Because some other members, including me, have had problems with unexpected entries in both From and To lines, I suspect that Mailman 3 does the DMARC enough differently
The only thing I can think of that might allow other lists to have author names for other lists but not for a Mailman list is that the MUAs are parsing email addresses out of the display name (which is a horrible risk, given the flexibility that users have in setting email headers, and especially display names). If there is no email address, then they completely ignore the content of the display name in favor of their preferred display name for the list.
My understanding is that all of the recent posts are missing the poster's name, after behaving as expected for some time. Something must have changed, but what is baffling me. If you have any further ideas, fine, but don't waste a lot of time on this.
MUA "upgrade" seems like as likely an explanation as any. I think if you want to know details what's going on for a particular user, their MUA's support channels are the best bet.
-- GNU Mailman consultant (installation, migration, customization) Sirius Open Source https://www.siriusopensource.com/ Software systems consulting in Europe, North America, and Japan
participants (3)
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Mark Sapiro -
Stephen J. Turnbull -
Steve Brown