How to configure outgoing mail in PHP + Exim bundle?

Question

PHP

Once upon a time, I set up a PHP + Exim4 bundle in Debian so that outgoing mail from PHP would not slow down the script when connected to a remote server, but would send letters to the local one, which in turn would redirect to the outgoing smtp server. Everything worked fine for several years, but it took another outgoing mailbox to be added. The box was brought on the mail server (remote). Added one more line with a mailbox to the file /etc/exim4/passwd.clien, like this:
smtp.remotehost.ru:[email protected]:mypassword
Reloaded exim4 for reliability. And in the PHP script, instead of the first box, I specify a new one.
The letters don't go away. Exim4\mainlog is getting errors on outgoing mail:
SMTP error from remote mail server after MAIL FROM: SIZE=5222 [email protected]: host smtp.yandex.ru [2a02:6b8::38]: 553 5.7.1 Sender address rejected: not owned by auth user.
Am I forgetting to set something up somewhere? Why is authorization not being carried out? Those. trying to log in xs from whom \ what? There is no such problem with the first box.