diff --git a/Application/Controller/Admin/MailConfigCheck.php b/Application/Controller/Admin/MailConfigCheck.php
index 253004d..4ea18fc 100644
--- a/Application/Controller/Admin/MailConfigCheck.php
+++ b/Application/Controller/Admin/MailConfigCheck.php
@@ -74,8 +74,7 @@ class MailConfigCheck extends AdminDetailsController
     {
         try {
 			$shop = Registry::getConfig()->getActiveShop();
-            $config = Registry::getConfig();
-			
+
             $mail = oxNew(Email::class);
             $mail->setRecipient(
                 trim(Registry::getRequest()->getRequestEscapedParameter('recipient')) ?: $this->testMailAddress
@@ -83,8 +82,7 @@ class MailConfigCheck extends AdminDetailsController
             $mail->setBody('.');
 			$mail->setFrom($shop->getFieldData('oxowneremail'));
 
-            $currentDebug = $config->getConfigParam('iDebug');
-            $config->setConfigParam('iDebug', 6);
+            $mail->set("SMTPDebug", true);  // don't set via iDebug = 6 because different handling
             $mail->setSmtp();
 
             ob_start();
@@ -95,8 +93,6 @@ class MailConfigCheck extends AdminDetailsController
             $re = '/(^|\<br\>)(\d{4}-\d{2}-\d{2}\s\d{2}:\d{2}:\d{2}\s)/m';
             $subst = "$1";
             $communication = preg_replace($re, $subst, $communication);
-
-            $config->setConfigParam('iDebug', $currentDebug);
             $this->addTplParam('mailer', $mail->getMailer());
             $this->addTplParam('communication', $communication);
         } catch (Exception $e) {