Add mail from override configuration

.env.sample

@@ -153,3 +153,11 @@ DB_FLAVOR=sqlite
 # COMPOSE_FILE="compose.yml:compose.mailman.yml"
 # MAILMAN_CORE_VOLUME=lists_example_com_mailman-core
 # MAILMAN_CORE_NETWORK=lists_example_com_internal
+
+###################################
+# SASL account -> MAIL FROM mappings for more liberal MAIL FROM relaying
+# return-path: https://www.rubydoc.info/gems/actionmailer-rack-upgrade-2/2.3.15/ActionMailer/Base
+# logins and MAIL FROM ownership: http://www.postfix.com/postconf.5.html#smtpd_relay_restrictions
+# there is an open ticket with a further discussion also https://github.com/Mailu/Mailu/issues/1096
+###################################
+# COMPOSE_FILE="compose.yml:compose.mailfrom.yml"

abra.sh

@@ -1,2 +1,3 @@
 export CERTDUMPER_POST_VERSION=v1
 export POSTFIX_OVERRIDE_VERSION=v10
+export SENDER_LOGIN_VERSIONS=v1

compose.mailfrom.yml

@@ -0,0 +1,17 @@
+version: "3.6"
+
+services:
+  smtp:
+    configs:
+      - source: mailfrom_overrides
+        target: /overrides/postfix.cf
+      - source: sender_logins
+        target: /overrides/sender_logins
+
+configs:
+  mailfrom_overrides:
+    name: ${STACK_NAME}_mailfrom_overrides_${POSTFIX_OVERRIDE_VERSION}
+    file: postfix.mailfrom.cf
+  sender_logins:
+    name: ${STACK_NAME}_sender_logins_${SENDER_LOGIN_VERSIONS}
+    file: sender_logins

postfix.mailfrom.cf

@@ -0,0 +1,3 @@
+# https://github.com/Mailu/Mailu/issues/1096
+
+smtpd_sender_login_maps = unionmap:{${podop}senderlogin, pcre:/overrides/sender_logins}