My project is doing testing of our mailing lists and came across what appears to be a bug. I believe it's not but she insists that it is. So before I do a bunch of research I wanted to post my steps to reproduce and ask for input. I'm including the full (redacted) mailing list config at the bottom of this post for reference.
* I have a closed mailing list, acme-clo...@foo.com * That mailing list has multiple subscribers, including user-1. I confirmed this by shelling into our server and running `mailman members acme-clo...@foo.com --role=any` on the OS command line. This showed all of the subscribers, including user-1. * I sent an mail FROM user-1 TO acme-closed, and it was received. And by that I mean I received an email TO acme-closed, FROM user-1. I also received the same email emails sent to the other subscribers since I use a catch all address for local testing. * In our system I closed user-1's account (which removes that user from the mailing list). I confirmed this by running the `mailman members` command and noting that user-1 was no longer a subscriber. * I sent another mail FROM user-1 TO acme-closed, and received two emails. One showed what appears to be a successful send to the mailing list. It showed acme-closed as the TO address, and user-1 as the sender. But I also received a second email TO user-1 FROM acme-closed whose body reads "Your message to the Acme-closed mailing-list was rejected for the following reasons: The message is not from a list member. The original message as received by Mailman is attached." So my PM is insistent that the first email is proof that there's a bug. "No e-mail sent from an e-mail address for a closed account should be sent to the mailing list." I on the other hand am arguing that the second email is proof that the email _wasn't_ actually sent to the list, and was instead a sort of bounceback to the user, However it's tough to argue with her logic because I agree the first email seems to have been incorrectly sent. Can you help me understand why the first email was sent, and if there's a way to prove with certainty that Mailman is behaving correctly? ``` accept_these_nonmembers: [] acceptablealias: [] admin_immed_notify: True admin_notify_mchanges: True administrators: [5 <Members>] administrivia: True advertised: False allow_list_posts: True anonymous_list: False archive_policy: ArchivePolicy.private archive_rendering_mode: ArchiveRenderingMode.text autorespond_owner: ResponseAction.none autorespond_postings: ResponseAction.none autorespond_requests: ResponseAction.none autoresponse_grace_period: 90 days, 0:00:00 autoresponse_owner_text: autoresponse_postings_text: autoresponse_request_text: bounce_info_stale_after: 7 days, 0:00:00 bounce_matching_headers: bounce_notify_owner_on_bounce_increment: False bounce_notify_owner_on_disable: True bounce_notify_owner_on_removal: True bounce_score_threshold: 5 bounce_you_are_disabled_warnings: 3 bounce_you_are_disabled_warnings_interval: 7 days, 0:00:00 bounces_address: acme-closed-boun...@foo.com collapse_alternatives: True convert_html_to_plaintext: False created_at: 2025-07-18 17:22:54.921936 data_path: /var/mailman/lists/acme-clos...@foo.com default_member_action: Action.accept default_nonmember_action: Action.reject description: closed digest_is_default: False digest_last_sent_at: None digest_members: [] digest_send_periodic: True digest_size_threshold: 30.0 digest_volume_frequency: DigestFrequency.monthly digests_enabled: True discard_these_nonmembers: [] display_name: Acme-closed dmarc_addresses: [] dmarc_mitigate_action: DMARCMitigateAction.munge_from dmarc_mitigate_unconditionally: False dmarc_moderation_notice: dmarc_wrapped_message_text: domain: <Domain @foo.com> emergency: False encode_ascii_prefixes: False filter_action: FilterAction.discard filter_content: False filter_extensions: [] filter_types: [] first_strip_reply_to: None forward_auto_discards: True forward_unrecognized_bounces_to: UnrecognizedBounceDisposition.discard fqdn_listname: acme-clo...@foo.com gateway_to_mail: False gateway_to_news: False hold_these_nonmembers: [] id: 2 include_rfc2369_headers: True info: join_address: acme-closed-j...@foo.com last_digest_recipients: [] last_post_at: 2025-07-18 17:26:28.155475 leave_address: acme-closed-le...@foo.com linked_newsgroup: list_id: acme-clos...@foo.com list_name: acme-closed mail_host: @foo.com max_days_to_hold: 0 max_message_size: 20000 max_num_recipients: 0 member_moderation_notice: member_roster_visibility: RosterVisibility.moderators members: [6 members] metadata: MetaData() moderator_password: None moderators: [5 Members] newsgroup_moderation: NewsgroupModeration.none next_digest_number: 1 next_request_id: 1 nntp_prefix_subject_too: True no_reply_address: nore...@foo.com nonmember_rejection_notice: nonmembers: [2 Members] obscure_addresses: True owner_address: acme-closed-ow...@foo.com owner_chain: default-owner-chain owner_pipeline: default-owner-pipeline owners: [] pass_extensions: [] pass_types: [] personalize: Personalization.none post_id: 2 posting_address: acme-clo...@foo.com posting_chain: default-posting-chain posting_pipeline: default-posting-pipeline preferred_language: <Language [en] English (USA)> process_bounces: False regular_members: [6 Members] reject_these_nonmembers: [] reply_goes_to_list: ReplyToMunging.no_munging reply_to_address: None request_address: acme-closed-requ...@foo.com require_explicit_destination: True respond_to_post_requests: False scrub_nondigest: False send_goodbye_message: False send_welcome_message: False subject_prefix: [Acme-closed] subscribe_address: acme-closed-subscr...@foo.com subscribers: 13 Members] subscription_policy: SubscriptionPolicy.moderate topics: [] topics_bodylines_limit: 5 topics_enabled: False unsubscribe_address: acme-closed-unsubscr...@foo.com unsubscription_policy: SubscriptionPolicy.confirm usenet_watermark: None volume: 1 ``` _______________________________________________ Mailman-users mailing list -- mailman-users@mailman3.org To unsubscribe send an email to mailman-users-le...@mailman3.org https://lists.mailman3.org/mailman3/lists/mailman-users.mailman3.org/ Archived at: https://lists.mailman3.org/archives/list/mailman-users@mailman3.org/message/XO4NFRKKUTH336SC5XO7ELCCFHHEEELX/ This message sent to arch...@mail-archive.com
