Why is mail not being sent?

Question

1C-Bitrix

Good afternoon.
Has anyone encountered this error when sending mail?
Bitrix does not give any errors when checking the system, test letters are sent successfully. But neither when placing an order, nor changing order statuses, letters are delivered to buyers, and in general neither the sender nor the recipients are determined:

Jul 13 11:47:02 host=smtp.mail.ru tls=on auth=on [email protected]*****.ru from=bitrix recipients=bitrix smtpstatus=501 smtpmsg='501 : sender address must contain a domain' errormsg='envelope from address bitrix not accepted by the server' exitcode=EX_DATAERR
Jul 13 11:48:02 host=smtp.mail.ru tls=on auth=on [email protected]*****.ru from =bitrix recipients=bitrix smtpstatus=501 smtpmsg='501 : sender address must contain a domain' errormsg='envelope from address bitrix not accepted by the server' exitcode=EX_DATAERR

Answer 1

these 2 letters are similar to notification cron
in crontab -e add >/dev/null 2>&1 at the end of each line and your log will not be clogged with them
and letters from the engine may not be sent for various reasons