diff --git a/src/applications/metamta/replyhandler/PhabricatorMailReplyHandler.php b/src/applications/metamta/replyhandler/PhabricatorMailReplyHandler.php
--- a/src/applications/metamta/replyhandler/PhabricatorMailReplyHandler.php
+++ b/src/applications/metamta/replyhandler/PhabricatorMailReplyHandler.php
@@ -254,10 +254,19 @@
       $map = $to + $cc;
 
       foreach ($map as $phid => $user) {
+        // Preserve the original To/Cc information on the target.
+        if (isset($to[$phid])) {
+          $target_to = array($phid => $user);
+          $target_cc = array();
+        } else {
+          $target_to = array();
+          $target_cc = array($phid => $user);
+        }
+
         $target = id(clone $template)
           ->setViewer($user)
-          ->setToMap(array($phid => $user))
-          ->setCCMap(array());
+          ->setToMap($target_to)
+          ->setCCMap($target_cc);
 
         if ($supports_private_replies) {
           $reply_to = $this->getPrivateReplyHandlerEmailAddress($user);