Thanks for your responses. I just did a few tests and I changed my config the following way for the mailing:
mailman.cfg <<<<< [mta] incoming: mailman.mta.postfix.LMTP outgoing: mailman.mta.deliver.deliver lmtp_host: 127.0.0.1 lmtp_port: 8024 smtp_host: localhost smtp_port: 25 verp_confirmations: no verp_personalized_deliveries: no verp_delivery_interval: 0 verp_delimiter: +
postconf -n <<<<< alias_database = hash:/etc/aliases alias_maps = hash:/etc/aliases append_dot_mydomain = no biff = no compatibility_level = 3.6 inet_interfaces = all inet_protocols = all local_recipient_maps = hash:/opt/mailman/mm/var/data/postfix_lmtp mailbox_size_limit = 0 mydestination = $myhostname, mailing.tester.de, localhost.tester.de, , localhost myhostname = mailing.tester.de mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128 myorigin = /etc/mailname owner_request_special = no readme_directory = no recipient_delimiter = + relay_domains = hash:/opt/mailman/mm/var/data/postfix_domains relayhost = [172.25.10.24]:25 smtp_tls_CApath = /etc/ssl/certs smtp_tls_security_level = may smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache smtpd_banner = $myhostname ESMTP $mail_name (Debian/GNU) smtpd_relay_restrictions = permit_mynetworks permit_sasl_authenticated defer_unauth_destination smtpd_tls_cert_file = /etc/ssl/certs/ssl-cert-snakeoil.pem smtpd_tls_key_file = /etc/ssl/private/ssl-cert-snakeoil.key smtpd_tls_security_level = may transport_maps = hash:/opt/mailman/mm/var/data/postfix_lmtp unknown_local_recipient_reject_code = 550
When I try to subscribe to a list called "Smartcity" the email is processed and the smtp.log shows the following lines: <<<<< Nov 27 20:53:38 2025 (146986) <176427321849.147026.3535542433696669790@tester-test-mailman.tester.local> smtp to smartcity@mailing.tester.de for 1 recips, completed in 0.032538414001464844 seconds Nov 27 20:53:38 2025 (146986) <176427321849.147026.3535542433696669790@tester-test-mailman.tester.local> post to smartcity@mailing.tester.de from smartcity-owner@mailing.tester.de, 999 bytes Nov 27 20:53:38 2025 (146985) Available AUTH mechanisms: LOGIN(builtin) PLAIN(builtin) Nov 27 20:53:38 2025 (146985) Peer: ('127.0.0.1', 40180) Nov 27 20:53:38 2025 (146985) ('127.0.0.1', 40180) handling connection Nov 27 20:53:38 2025 (146985) ('127.0.0.1', 40180) >> b'LHLO mailing.tester.de' Nov 27 20:53:38 2025 (146985) ('127.0.0.1', 40180) >> b'MAIL FROM:<smartcity-bounces@mailing.tester.de> SIZE=1241' Nov 27 20:53:38 2025 (146985) ('127.0.0.1', 40180) sender: smartcity-bounces@mailing.tester.de Nov 27 20:53:38 2025 (146985) ('127.0.0.1', 40180) >> b'RCPT TO:<smartcity-owner@mailing.tester.de>' Nov 27 20:53:38 2025 (146985) ('127.0.0.1', 40180) recip: smartcity-owner@mailing.tester.de Nov 27 20:53:38 2025 (146985) ('127.0.0.1', 40180) >> b'DATA' Nov 27 20:53:38 2025 (146985) ('127.0.0.1', 40180) >> b'QUIT' Nov 27 20:53:38 2025 (146985) ('127.0.0.1', 40180) connection lost Nov 27 20:53:38 2025 (146985) ('127.0.0.1', 40180) Connection lost during _handle_client() Nov 27 20:53:40 2025 (146986) <176427321849.147026.3535542433696669790@tester-test-mailman.tester.local> smtp to smartcity@mailing.tester.de for 1 recips, completed in 0.009531497955322266 seconds Nov 27 20:53:40 2025 (146986) <176427321849.147026.3535542433696669790@tester-test-mailman.tester.local> post to smartcity@mailing.tester.de from smartcity-owner@mailing.tester.de, 1241 bytes Nov 27 20:53:40 2025 (146985) Available AUTH mechanisms: LOGIN(builtin) PLAIN(builtin) Nov 27 20:53:40 2025 (146985) Peer: ('127.0.0.1', 40190) Nov 27 20:53:40 2025 (146985) ('127.0.0.1', 40190) handling connection Nov 27 20:53:40 2025 (146985) ('127.0.0.1', 40190) >> b'LHLO mailing.tester.de' Nov 27 20:53:40 2025 (146985) ('127.0.0.1', 40190) >> b'MAIL FROM:<> SIZE=3666 BODY=8BITMIME' Nov 27 20:53:40 2025 (146985) ('127.0.0.1', 40190) sender: <> Nov 27 20:53:40 2025 (146985) ('127.0.0.1', 40190) >> b'RCPT TO:<smartcity-bounces+johannes.wolf=tester.de@mailing.tester.de>' Nov 27 20:53:40 2025 (146985) ('127.0.0.1', 40190) recip: smartcity-bounces+johannes.wolf=tester.de@mailing.tester.de Nov 27 20:53:40 2025 (146985) ('127.0.0.1', 40190) >> b'DATA' Nov 27 20:53:40 2025 (146985) ('127.0.0.1', 40190) >> b'QUIT' Nov 27 20:53:40 2025 (146985) ('127.0.0.1', 40190) connection lost Nov 27 20:53:40 2025 (146985) ('127.0.0.1', 40190) Connection lost during _handle_client()
mailman.log <<<<< [27/Nov/2025:20:53:31 +0100] "GET /3.1/lists/smartcity.mailing.tester.de HTTP/1.1" 200 446 "-" "GNU Mailman REST client v3.3.5" [27/Nov/2025:20:53:31 +0100] "GET /3.1/lists/smartcity@mailing.tester.de/requests?token_owner=subscriber&request_type=subscription HTTP/1.1" 200 90 "-" "GNU Mailman REST client v3.3.5" [27/Nov/2025:20:53:31 +0100] "GET /3.1/lists/smartcity@mailing.tester.de/requests/count?token_owner=moderator HTTP/1.1" 200 73 "-" "GNU Mailman REST client v3.3.5" [27/Nov/2025:20:53:31 +0100] "GET /3.1/lists/smartcity@mailing.tester.de/held/count HTTP/1.1" 200 73 "-" "GNU Mailman REST client v3.3.5" [27/Nov/2025:20:53:32 +0100] "GET /3.1/lists/smartcity.mailing.tester.de HTTP/1.1" 200 446 "-" "GNU Mailman REST client v3.3.5" [27/Nov/2025:20:53:32 +0100] "GET /3.1/lists/smartcity@mailing.tester.de/requests?token_owner=moderator&request_type=subscription HTTP/1.1" 200 90 "-" "GNU Mailman REST client v3.3.5" [27/Nov/2025:20:53:32 +0100] "GET /3.1/lists/smartcity@mailing.tester.de/requests/count?token_owner=moderator HTTP/1.1" 200 73 "-" "GNU Mailman REST client v3.3.5" [27/Nov/2025:20:53:32 +0100] "GET /3.1/lists/smartcity@mailing.tester.de/held/count HTTP/1.1" 200 73 "-" "GNU Mailman REST client v3.3.5" Nov 27 20:53:38 2025 (147026) smartcity@mailing.tester.de: held subscription request from jowo@kaaw.de [27/Nov/2025:20:53:38 +0100] "POST /3.1/members HTTP/1.0" 202 142 "-" "-" Nov 27 20:53:39 2025 (146984) OWNER: <176427321849.147026.3535542433696669790@tester-test-mailman.tester.local>
On my relaying mail host the email is coming up in "MAIL FROM" is set "smartcity-bounces+johannes.wolf=tester.de@mailing.tester.de" but the fields "Header-From", "Recipient" and "subject" are empty. Why is the e-mail passed to my MTA but the adresses are not resolved correctly from before in Mailman3?
Thanks and regards