Good afternoon.
In the integration settings there is a checkbox "Do not send emails from this mail if SMTP is not available"
If you set it, then letters will be sent strictly using the SMTP server.
And you will see the error "SMTP: SMTP FAIL connect for login: zakazchado@***"
You saw an error, unchecked it and decided that this is how it would work...
In konrne is not the right idea about the operation of the system!
Your integration is not configured correctly, configure the integration correctly and everything will work.
Without this checkbox set, in case of an error connecting to the SMTP server, mail is sent directly from the box server.
And such letters are usually rejected by plchtovy resources.
You can also look at the logs
https://chado.1b.app/app/app-api/sendmail-2023-02-17.log
Correct send method: [5] => method: smtp
With method: mail, the kidney will not die.