[Postfix] Lookup credentials for user-specific sender transports

data/Dockerfiles/postfix/postfix.sh

@@ -181,11 +181,31 @@ hosts = unix:/var/run/mysqld/mysqld.sock
 dbname = ${DBNAME}
 query = SELECT CONCAT_WS(':', username, password) AS auth_data FROM relayhosts
   WHERE id IN (
-    SELECT relayhost FROM domain
-      WHERE CONCAT('@', domain) = '%s'
-      OR domain IN (
-        SELECT target_domain FROM alias_domain WHERE CONCAT('@', alias_domain) =  '%s'
+    SELECT COALESCE(
+      (SELECT id FROM relayhosts
+      LEFT OUTER JOIN domain ON domain.relayhost = relayhosts.id
+      WHERE relayhosts.active = '1'
+        AND (domain.domain = '%d'
+          OR domain.domain IN (
+            SELECT target_domain FROM alias_domain
+            WHERE alias_domain = '%d'
+          )
+        )
+      ),
+      (SELECT id FROM relayhosts
+      LEFT OUTER JOIN mailbox ON JSON_UNQUOTE(JSON_VALUE(mailbox.attributes, '$.relayhost')) = relayhosts.id
+      WHERE relayhosts.active = '1'
+        AND (
+          mailbox.username IN (
+            SELECT alias.goto from alias
+              JOIN mailbox ON mailbox.username = alias.goto
+                WHERE alias.active = '1'
+                  AND alias.address = '%s'
+                  AND alias.address NOT LIKE '@%%'
+          )
+        )
       )
+    )
   )
   AND active = '1'
   AND username != '';