connection: assure remote is connected before queue (#3338)

- immediately before queuing, check that remote is still connected

Changes.md

@@ -8,6 +8,7 @@
 #### Changed
 
 - bounce: repackaged plugin as NPM module #3341
+- connection: check remote is connected before queue #3338
 - transaction: init with conn.init_transaction, always pass in cfg #3315
 - check for local_mx only when default route is used #3307
 - dkim: repackaged as NPM module #3311

connection.js

@@ -3,10 +3,8 @@
 
 // node.js built-in libs
 const dns         = require('dns');
-const fs          = require('fs');
 const net         = require('net');
 const os          = require('os');
-const path        = require('path');
 
 // npm libs
 const ipaddr      = require('ipaddr.js');
@@ -1738,6 +1736,7 @@ class Connection {
         }
     }
     queue_outbound_respond (retval, msg) {
+        if (this.remote.closed) return;
         if (!msg) msg = this.queue_msg(retval, msg) || 'Message Queued';
         this.store_queue_result(retval, msg);
         msg = `${msg} (${this.transaction.uuid})`;
@@ -1894,4 +1893,4 @@ exports.createConnection = (client, server, cfg) => {
     return new Connection(client, server, cfg);
 }
 
-logger.add_log_methods(Connection)
+logger.add_log_methods(Connection)

plugins/queue/smtp_forward.js

@@ -230,6 +230,7 @@ exports.forward_enabled = function (conn, dom_cfg) {
 
 exports.queue_forward = function (next, connection) {
     const plugin = this;
+    if (connection.remote.closed) return
     const txn = connection?.transaction;
 
     const cfg = plugin.get_config(connection);