--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/plugins/additional_message_headers/additional_message_headers.php	Thu Jan 04 15:50:29 2018 -0500
@@ -0,0 +1,37 @@
+<?php
+
+/**
+ * Additional Message Headers
+ *
+ * Very simple plugin which will add additional headers
+ * to or remove them from outgoing messages.
+ *
+ * Enable the plugin in config.inc.php and add your desired headers:
+ * $config['additional_message_headers'] = array('User-Agent' => 'My-Very-Own-Webmail');
+ *
+ * @author Ziba Scott
+ * @website http://roundcube.net
+ */
+class additional_message_headers extends rcube_plugin
+{
+    function init()
+    {
+        $this->add_hook('message_before_send', array($this, 'message_headers'));
+    }
+
+    function message_headers($args)
+    {
+        $this->load_config();
+
+        $rcube = rcube::get_instance();
+
+        // additional email headers
+        $additional_headers = $rcube->config->get('additional_message_headers', array());
+
+        if (!empty($additional_headers)) {
+            $args['message']->headers($additional_headers, true);
+        }
+
+        return $args;
+    }
+}