On 9/9/24 15:12, Steve Brown via Mailman-users wrote:
Looking at the headers of emails sent from steve@stevebrown.us to the list and boomeranged back to me, I see a line “X-MailFrom: bounce+66273f.99dcd9c-radg=lists.radg.us@stevebrown.us”. I gather that it is designating the return path where a message would be sent if there was a delivery problem. From its position in the header, I suspect it is added as they pass through Mailgun, maybe related to DKIM.
Without seeing the full headers in sequence I can't say much, but some MTA in the delivery chain (likely your MX, mx1.tmdhosting.com) is setting the envelope sender of the message to bounce+66273f.99dcd9c-radg=lists.radg.us@stevebrown.us so that it can receive DSNs at that address. Mailman's lmtp runner is adding the X-MailFrom: header as information.
Then Mailman's incoming runner ensures that all of the messages senders
are known to mailman by creating, if necessary, address records for all
of them. See
<https://gitlab.com/mailman/mailman/-/blob/master/src/mailman/runners/incoming.py?ref_type=heads#L73-75>.
The senders are defined as addresses in the headers listed in
the configuration setting sender_headers, default = from, from_
meaning envelope sender, reply-to and sender. See
<https://gitlab.com/mailman/mailman/-/blob/master/src/mailman/config/schema.cfg?ref_type=heads#L40-45>
I am hoping you might know why that bounce address is recognized by Mailman 3 as a real address for my emails, but not for others, even from my wife’s computer traversing the same path from our home to the Mailman 3 server. The Mailman installation does get and process the post, but also puts the “bounce+,,,” address in its list of nonmembers. Mailmanlists.net hasn’t figured out the behavior. I can provide full header information if that would help. My understanding of how headers work is very limited.
Are you saying that the bounce+... address ends up as a nonmember of
the list you are sending to. I don't think that should happen. Mailman
will add the sender address as a nonmember of the list if it is not a
member, but the sender is the first non-empty value in senders which
normally would be the From: address unless the installation has changed
the sender_headers setting
-- Mark Sapiro <mark@msapiro.net> The highway is for gamblers, San Francisco Bay Area, California better use your sense - B. Dylan