diff --git a/test/docker_mail/templates/mailu.env b/test/docker_mail/templates/mailu.env
index 0b2456467922701ce0332f6b553d69e8b3cb8ad4..7c84a63d95048a938547b84ab0cd99248dde283a 100644
--- a/test/docker_mail/templates/mailu.env
+++ b/test/docker_mail/templates/mailu.env
@@ -93,6 +93,7 @@ FETCHMAIL_ENABLED=False
 FETCHMAIL_DELAY=600
 
 # Recipient delimiter, character used to delimiter localpart from custom address part
+# must be set to + for mailman
 RECIPIENT_DELIMITER=+
 
 # DMARC rua and ruf email
diff --git a/test/docker_mail/templates/mailu/overrides/postfix/postfix.cf b/test/docker_mail/templates/mailu/overrides/postfix/postfix.cf
index d91a5707ab423cb050f575fb4e6fcbec8ae51df8..9cb2d76780c6930320d943ae9f02f3ce7249684c 100644
--- a/test/docker_mail/templates/mailu/overrides/postfix/postfix.cf
+++ b/test/docker_mail/templates/mailu/overrides/postfix/postfix.cf
@@ -2,13 +2,13 @@
 # Overrides for mailman3 integration 
 # see https://patrick.georgi.family/2019/01/12/combining-mailman-3-with-mailu/
 
+always_add_missing_headers = yes
 append_at_myorigin=no
 append_dot_mydomain=no
-recipient_delimiter = +
-unknown_local_recipient_reject_code = 550
+local_header_rewrite_clients = permit_sasl_authenticated
 owner_request_special = no
-virtual_mailbox_maps = regexp:/opt/mailman/postfix_lmtp \${podop}mailbox
-transport_maps = regexp:/opt/mailman/postfix_lmtp \lmdb:/etc/postfix/transport.map \${podop}transport
+unknown_local_recipient_reject_code = 550
+
 local_recipient_maps = regexp:/opt/mailman/postfix_lmtp
-always_add_missing_headers = yes
-local_header_rewrite_clients = permit_sasl_authenticated
+transport_maps = regexp:/opt/mailman/postfix_lmtp \lmdb:/etc/postfix/transport.map \${podop}transport
+virtual_mailbox_maps = regexp:/opt/mailman/postfix_lmtp \${podop}mailbox