Your software
My Mautic version is: v6.0.4
My PHP version is: 8.3.6
My Database type and version is: Doctrine driver pdo_mysql, 10.11.13-MariaDB-0ubuntu0.24.04.1
Your problem
My problem is: I cannot sent e-mails, I get error codes but can’t seem to fix it by myself. What an I missing here?
These errors are showing in the log:
When I want to send a custom e-mail: Failed to send to xxxx@xxxxx.nl: Failed to authenticate on SMTP server with username “xxxx@xxxxxx.nl” using the following authenticators: “LOGIN”, “PLAIN”. Authenticator “LOGIN” returned “Expected response code “235” but got code “535”, with message “535 5.7.8 Error: authentication failed: UGFzc3dvcmQ6”.”. Authenticator “PLAIN” returned “Expected response code “235” but got code “535”, with message “535 5.7.8 Error: authentication failed: UGFzc3dvcmQ6”.”.
And the log:
[2025-09-17T00:02:27.369214+00:00] mautic.ERROR: Uncaught PHP Exception Symfony\Component\HttpKernel\Exception\BadRequestHttpException: “Untrusted Host “213.199.63.178”.” at /var/www/mautic-app/vendor/symfony/http-kernel/HttpKernel.php line 83 {“exception”:“[object] (Symfony\\Component\\HttpKernel\\Exception\\BadRequestHttpException(code: 0): Untrusted Host \“213.199.63.178\”. at /var/www/mautic-app/vendor/symfony/http-kernel/HttpKernel.php:83)\n[previous exception] [object] (Symfony\\Component\\HttpFoundation\\Exception\\SuspiciousOperationException(code: 0): Untrusted Host \“213.199.63.178\”. at /var/www/mautic-app/vendor/symfony/http-foundation/Request.php:1186)”} {“hostname”:“vmd176712”,“pid”:1740045}
[2025-09-17T00:02:27.430441+00:00] mautic.CRITICAL: Exception thrown when handling an exception (Twig\Error\RuntimeError: An exception has been thrown during the rendering of a template (“There is currently no session available.”). at /var/www/mautic-app/app/bundles/CoreBundle/Resources/views/Default/script.html.twig line 9) {“exception”:“[object] (Twig\\Error\\RuntimeError(code: 0): An exception has been thrown during the rendering of a template (\“There is currently no session available.\”). at /var/www/mautic-app/app/bundles/CoreBundle/Resources/views/Default/script.html.twig:9)\n[previous exception] [object] (Symfony\\Component\\HttpFoundation\\Exception\\SessionNotFoundException(code: 0): There is currently no session available. at /var/www/mautic-app/vendor/symfony/http-foundation/RequestStack.php:107)”} {“hostname”:“vmd176712”,“pid”:1740045}
[2025-09-17T00:02:27.447903+00:00] mautic.ERROR: Twig\Error\RuntimeError: An exception has been thrown during the rendering of a template (“There is currently no session available.”). - in file /var/www/mautic-app/app/bundles/CoreBundle/Resources/views/Default/script.html.twig - at line 9 {“hostname”:“vmd176712”,“pid”:1740045}
Steps I have tried to fix the problem: change the mail adress from sender and check if DSN test mail works, and it does.
