Mailer: SMTP Error: 454 4.7.1

Need Help
1

Hi all,
I am still fighting with mail delivery in my application.
The error log below proves the first RECIPIENT is access denied = not the sender.
My Hosting-support tells me the sender is denied, but thats wrong.
I asume it is a configuration/autentication problem.
Sometimes mails are delivered, mainly when it is in the same domain with the sender.
Where can I start with more research?
Regards Klaus

2025-02-12 17:57:30 error: Categories found
2025-02-12 17:57:30 error: Mail-tostefan.tillinger@t-online.de
2025-02-12 17:57:30 error: Mail-todorotheacastor@online.de
2025-02-12 17:57:30 error: Mail-toreg.henss@web.de
2025-02-12 17:57:30 error: Mail-tobheydekamp@gmx.de
2025-02-12 17:57:30 error: Mail-torachlema.sponsel@t-online.de
2025-02-12 17:57:30 error: Mail-torepair-mainsp.jsm@t-online.de
2025-02-12 17:57:30 error: Mail-tochristinefeysponsel@gmail.com
2025-02-12 17:57:30 error: Mail-toremmel-fassbender@t-online.de
2025-02-12 17:57:34 error: [Cake\Network\Exception\SocketException] SMTP Error: 454 4.7.1 stefan.tillinger@t-online.de:
Relay access denied in /var/www/web489/html/totaltest/vendor/cakephp/cakephp/src/Mailer/Transport/SmtpTransport.php on line 632
Stack Trace:

  • /var/www/web489/html/totaltest/vendor/cakephp/cakephp/src/Mailer/Transport/SmtpTransport.php:532
  • /var/www/web489/html/totaltest/vendor/cakephp/cakephp/src/Mailer/Transport/SmtpTransport.php:206
  • /var/www/web489/html/totaltest/vendor/cakephp/cakephp/src/Mailer/Mailer.php:407
  • /var/www/web489/html/totaltest/src/Controller/Component/controllerComponent.php:89
  • /var/www/web489/html/totaltest/src/Controller/MeetingsController.php:157
  • /var/www/web489/html/totaltest/vendor/cakephp/cakephp/src/Controller/Controller.php:560
  • /var/www/web489/html/totaltest/vendor/cakephp/cakephp/src/Controller/ControllerFactory.php:140
  • /var/www/web489/html/totaltest/vendor/cakephp/cakephp/src/Controller/ControllerFactory.php:115
  • /var/www/web489/html/totaltest/vendor/cakephp/cakephp/src/Http/BaseApplication.php:325
  • /var/www/web489/html/totaltest/vendor/cakephp/cakephp/src/Http/Runner.php:86
  • /var/www/web489/html/totaltest/vendor/cakephp/cakephp/src/Http/Middleware/CsrfProtectionMiddleware.php:176
2

Hey Klaus, this

Mail-toremmel-fassbender@t-online.de

looks weird. For me I would say there is a space " " missing. Dont know if it has something to do with this.

If you say some mails will be delivered it could happen because of spam protection. Maybe you are trying to send to many mails per once?
I know for example the prpvider HostEurope has added some options you need to do before you can send mails via PHP script.

But this depends on your provider.

3

First off, I hope that you’ve edited those email addresses and aren’t just posting actual people’s contact information on a public forum.

As for the problem, are you able to email the problem address directly, using your normal email client? I wonder if that particular user has something set up on their account that’s causing this issue, and it’s actually nothing to do with your code.