# Mail sending error

**URL:** <https://discourse.cakephp.org/t/mail-sending-error/12413>\
**Category:** Need Help\
**Created:** [February 7, 2025, 5:45pm UTC](https://discourse.cakephp.org/t/mail-sending-error/12413 "2025-02-07T17:45:55Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Klaus](https://yyz1.discourse-cdn.com/flex029/user_avatar/discourse.cakephp.org/klaus/32/269_2.png) [@Klaus](https://discourse.cakephp.org/u/Klaus)\
**Post date:** [February 7, 2025, 5:45pm UTC](https://discourse.cakephp.org/t/mail-sending-error/12413/1 "2025-02-07T17:45:55Z")

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Hi all,  
I am using the Mailer in Cake for some years and it went well, but the below error occurs and the hosting provider identifies the mailadress as sender; but it is the receiver. How do I figuere out the real reason of this exception? Regards Klaus

2025-02-07 17:37:16 error: [Cake\Network\Exception\SocketException] SMTP Error: 454 4.7.1 [stefan.tillinger@t-online.de](mailto: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

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**Author:** ![der-dave](https://avatars.discourse-cdn.com/v4/letter/d/e47774/32.png) [@der-dave](https://discourse.cakephp.org/u/der-dave)\
**Post date:** [February 8, 2025, 10:29pm UTC](https://discourse.cakephp.org/t/mail-sending-error/12413/2 "2025-02-08T22:29:51Z")

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Hey Klaus,

read here:  
[454 4.7.0 Fehler bei der temporären Authentifizierung - Exchange | Microsoft Learn](https://learn.microsoft.com/de-de/exchange/troubleshoot/client-connectivity/454-4-7-0-temporary-authentication-failure)

Looks like there is some Authentication problem with the Exchange server. I would contact the provider again with your exact error code

```auto
SMTP Error: 454 4.7.1

```