diff --git a/src/PEAR2/Mail/Queue.php b/src/PEAR2/Mail/Queue.php
index 9a5456c..e162694 100644
--- a/src/PEAR2/Mail/Queue.php
+++ b/src/PEAR2/Mail/Queue.php
@@ -437,7 +437,7 @@ public function sendMail(Body $mail, $set_as_sent=true)
             );
         }
         $sent = $this->send_mail->send($recipient, $hdrs, $body);
-        if (($sent instanceof PEAR_Error) && $sent && $set_as_sent) {
+        if (!($sent instanceof PEAR_Error) && $sent && $set_as_sent) {
             $this->container->setAsSent($mail);
         }
         if (isset($this->send_mail->queued_as)) {