MDL-30698 forum: made message ID genuinely unique to prevent mail servers dropping...

diff --git a/mod/forum/lib.php b/mod/forum/lib.php
index f36d56e..5819b43 100644 (file)
--- a/mod/forum/lib.php
+++ b/mod/forum/lib.php
@@ -365,6 +365,9 @@ WHERE
     return $result;
 }
 
+function forum_get_email_message_id($postid, $usertoid, $hostname) {
+    return '<moodlepost'.$postid.'to'.$usertoid.'@'.$hostname.'>';
+}
 
 /**
  * Function to be run periodically according to the moodle cron
@@ -603,14 +606,14 @@ function forum_cron() {
                            'Precedence: Bulk',
                            'List-Id: "'.$cleanforumname.'" <moodleforum'.$forum->id.'@'.$hostname.'>',
                            'List-Help: '.$CFG->wwwroot.'/mod/forum/view.php?f='.$forum->id,
-                           'Message-ID: <moodlepost'.$post->id.'@'.$hostname.'>',
+                           'Message-ID: '.forum_get_email_message_id($post->id, $userto->id, $hostname),
                            'X-Course-Id: '.$course->id,
                            'X-Course-Name: '.format_string($course->fullname, true)
                 );
 
                 if ($post->parent) {  // This post is a reply, so add headers for threading (see MDL-22551)
-                    $userfrom->customheaders[] = 'In-Reply-To: <moodlepost'.$post->parent.'@'.$hostname.'>';
-                    $userfrom->customheaders[] = 'References: <moodlepost'.$post->parent.'@'.$hostname.'>';
+                    $userfrom->customheaders[] = 'In-Reply-To: '.forum_get_email_message_id($post->parent, $userto->id, $hostname);
+                    $userfrom->customheaders[] = 'References: '.forum_get_email_message_id($post->parent, $userto->id, $hostname);
                 }
 
                 $shortname = format_string($course->shortname, true, array('context' => get_context_instance(CONTEXT_COURSE, $course->id)));