Update: Ok I've wiped the entire file directory clean, dropped all tables, and started completely from scratch using PHP5.6. What I found if "New Message Alerts" are being sent IF 1) the customer created the ticket from the web interface or if 2) the customer creates the ticket through email AND an agent replies from the web interface.There is definitely no "New Message Alert" being sent if the customer replies to the original "New Ticket Opened" auto-responder before an agent logs into the web interface and also posts a comment.I've read through class.ticket.php and can't find the exact snippet of code controlling this, though I did experiment with several changes which were all unsuccessful. Here's some that stood out to me but I couldn't confirm through testing:(from includes/class.ticket.php)1) Section about skipping to log the status if there aren't any comments: // Log status change b4 reload — if currently has a status. (On new // ticket, the ticket is opened and thereafter the status is set to // the requested status). if ($hadStatus) { $alert = false; if ($comments = ThreadEntryBody:($comments)) { // Send out alerts if comments are included $alert = true; $this->logNote(__('Status Changed'), $comments, $thisstaff, $alert); } }2) Section about auto-reply but not to respond to bounces and other auto-replies. I wonder if a reply by the customer to the "New Ticket Opened" email is considered an auto-reply, but I couldn't find from grep "auto-reply" what osTicket is considering an auto-reply. // Do not auto-respond to bounces and other auto-replies $autorespond = isset($vars) ? !$vars && !$vars : true; $reopen = $autorespond; // Do not reopen bounces if ($autorespond && $message->isBounceOrAutoReply()) $autorespond = $reopen= false; elseif ($autorespond && isset($vars)) $autorespond = $vars; $this->onMessage($message, ($autorespond && $alerts), $reopen); //must be called b4 sending alerts to staff. if ($autorespond && $alerts && $cfg && $cfg->notifyCollabsONNewMessage()) $this->notifyCollaborators($message, array('signature' => '')); if (!($alerts && $autorespond)) return $message; //Our work is done...