The message looks like spam

If you sent a message from a Yandex address and received a non-delivery report that states: “Message rejected under suspicion of SPAM”, “Message rejected as spam by Content Filtering”, “ Message rejected. See for more information”, “Sorry, message looks like SPAM to me”, “550 5.7.1 SPF check failed: <IP_host> is not authorized to send in the name of <domain_name>. (in reply to RCPT TO command)” this means the recipient's mail server treats your email as spam.

Try contacting the recipient or their mail service administration by another method and report the problem.

If you are sending legitimate messages to your website users or subscribers, please read Yandex requirements for honest mailing lists.

Note. If you use Yandex 360 for Business, the SPF record must be set up on the linked domain.