Why does Bitrix spam when sending emails from the site?

Question

Bitrix24

When sending emails from forms, internal support messages, etc. in the msmtp logs, strange addresses that are not included in the list of established recipients are recorded in the recipients field. More than half are foreign (@aol.com, @yahoo.com, @me.com ...). At the same time, the admin mailbox, set in the msmtp file as user and from, is littered with letters from [email protected] such as "Undelivered message", "Letter sent to a non-existent address ...".
Sending works through smtp.yandex.ru.

What could be the problem?

Answer 1

because it is not configured - a gift to spammers