Hello Stephen,

Thanks for you well explaination. I configured verp_confirm_format: $address to strip the COOKIE. It's working now after I configured verp_confirm_format: $address+$cookie to [mta] section in file /etc/mailman3/mailman.cfg. and verified variable recipient_delimiter = + in file /etc/postfix/main.cf.

Thanks, Marin

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Marin Sok IT Director P 213.785.2556 | F 213.680.1727 http://www.lalawlibrary.org/<http://www.lalawlibrary.org/> | MSok@lalawlibrary.org Access to Information = Access to Justice

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From: Stephen J. Turnbull <steve@turnbull.jp> Sent: Monday, February 16, 2026 9:15 AM To: Marin Sok <MSok@lalawlibrary.org> Cc: mailman-users@mailman3.org <mailman-users@mailman3.org> Subject: [MM3-users] Reply to Confirmation Email During Subscribe Process Receiving ListName-Bounce@Domain

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msok--- via Mailman-users writes:

I just finished install it. I setup a test list with default settings as test1@domain. I added a user to the list via Mass Subscription with Pre confirm check and Pre approved check.

Inside the user inbox in GMail account received email from address test1-confirm@domain ( I added this erp_confirm_format: $address to [mta] in /etc/mailman3/mailman.cfg) with Your confirmation is needed to join the test1@domain mailing list.

This shouldn't happen if you check pre-confirmed. Also, the from address should be test1-confirm+COOKIE@domain, where COOKIE is a long string of random-looking characters.

I replied to the email and I received another email as test1-bounce@domain.

What was the content of this mail? The return address of "test1-bounce@domain" is normal. *Posts* via a mailing list are expected to be two-way (that is, it is normal, expected to behavior for users to reply to the list). The "test1-confirm" From address is used only on mail used to confirm ownership of an address or subscription to a mailing list by a user who is not logged in, but it should always contain a "+COOKIE" at the end. Most other "administrative" From addresses are the "test1-bounce" address, which is used for informative emails which are not expected to receive replies (as well as the hidden "envelope return" address which a mail server returns undeliverable mail to, thus the "bounce" name).

I went to my mailing test1@domain. I found a user that I tried to add list in 'Subscription request' under 'Pending Confirmation'.

This may be because something is stripping the COOKIE. If you have these emails saved, it will help to diagnose the problem if you send us the "raw" or "source" email, including all the header material that email clients usually hide.

-- GNU Mailman consultant (installation, migration, customization) Sirius Open Source https://www.siriusopensource.com/<https://www.siriusopensource.com/> Software systems consulting in Europe, North America, and Japan

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