Transaction failed Unauthorized sender address.

Hi @pixzilla

I hope you are doing well.

Please share the Post SMTP Diagnostic test report so I can get back to you with a solution.

Thanks and regards,
Support Team – WPExperts  

Mailer: postsmtp
HostName: bewegung-und-lernen.de
cURL Version: 7.74.0
OpenSSL Version: OpenSSL/1.1.1w
OS: Linux info 3.0 #1337 SMP Tue Jan 01 00:00:00 CEST 2000 all GNU/Linux
PHP: Linux 8.1.27 C.UTF-8
PHP Dependencies: iconv=Yes, spl_autoload=Yes, openssl=Yes, sockets=No, allow_url_fopen=Yes, mcrypt=No, zlib_encode=Yes
WordPress: 6.4.3 de_DE UTF-8
WordPress Theme: Avada
WordPress Plugins: 404 To Homepage, Advanced Database Cleaner PRO, Autoptimize, Blackhole for Bad Bots, BBQ Firewall, Borlabs Cookie – Cookie Opt-in, Conditional Fields for Contact Form 7, Honeypot for Contact Form 7, Contact Form 7, Duplicator Pro, Enable Media Replace, eRecht24 legal texts for WordPress, Avada Builder, Avada Core, Google Analytics Opt-Out, Site Kit by Google, Solid Security Pro, MainWP Child, Post SMTP, Regenerate Thumbnails Advanced, Slider Revolution, ShortPixel Image Optimizer, Yoast SEO, WP Statistics, WP Super Cache
WordPress wp_mail Owner: /homepages/42/d405020474/htdocs/bul-wp/wp-content/plugins/post-smtp/Postman/PostmanWpMailBinder.php
WordPress wp_mail Filter(s): PostsmtpMailer->get_mail_args
WordPress phpmailer_init Action(s): wpcf7_phpmailer_init, PostsmtpMailer->phpmailer_smtp_init
Postman: 2.8.11
Postman Sender Domain (Envelope|Message): bewegung-und-lernen.de | bewegung-und-lernen.de
Postman Prevent Message Sender Override (Email|Name): No | No
Postman Active Transport: Other SMTP (smtp:tls:plain://smtp.ionos.de:587)
Postman Active Transport Status (Ready|Connected): Yes | Yes
Postman Deliveries (Success|Fail): 281 | 5

Hi @pixzilla,

I hope you are doing well.

Thank you for providing us with the information. It seems like the theme or plugin overrides your ‘From email address’ and the email service you are using, only allows registered email addresses to send emails.

Please check the boxes “Prevent?plugins?and?themes?from changing this” below the fields of ‘From Email’ and ‘From Name’ in the Dashboard > All Settings > Message Tab.

I have attached a screenshot for your reference.

I hope this will help you.

Thanks and regards,
Support Team – WPExperts?

Yes! That solved the Problem. Thanks!