How to unlock the mail queue?

Question

Exim

I send letters via SMTP connection, on the server is exim 4.72.
I monitor the mail queue.
After Yandex sent 4000 letters to users, all other letters began to queue up. It reaches mail.ru and the rest, the problem is only in Yandex. More than 4000 letters are not sent.
I removed the sending limit per day in the config, it did not help.

Answer 1

you need to configure dkim letter signing - Yandex loves it. it is also good to start spf in dns-e.