diff --git a/lib/phpmailer/moodle_phpmailer.php b/lib/phpmailer/moodle_phpmailer.php
index a31d3c8961c..01cdadc018d 100644
--- a/lib/phpmailer/moodle_phpmailer.php
+++ b/lib/phpmailer/moodle_phpmailer.php
@@ -135,7 +135,7 @@ class moodle_phpmailer extends PHPMailer {
      */
     protected function PostSend() {
         // Now ask phpunit if it wants to catch this message.
-        if (phpunit_util::is_redirecting_messages()) {
+        if (PHPUNIT_TEST && phpunit_util::is_redirecting_messages()) {
             $mail = new stdClass();
             $mail->header = $this->MIMEHeader;
             $mail->body = $this->MIMEBody;