Why did the mail stop coming after I started using pdd.yandex.ru?

Question

Yandex

Recently moved to DigitalOcean from regular hosting. In order not to bathe with mail, I set up MX records on pdd.yandex.ru. There created the necessary postal addresses.
Now there was such problem - some letters are not delivered.
If a user sends a message on the "write to us" page, it is not delivered (moreover, it should be delivered to the site admin, in principle, this should not fall into spam, because you need to send a letter to yourself through Yandex)
If the user registers, he is not delivered his letter
If the user leaves an ad, the notification reaches the admin (and what is strange, I set redirection on the previous hosting, and it works for this type of letters, although I did not set redirection on pdd.yandex)
I looked everywhere in spam - there is nothing anywhere. What to do?

Answer 1

They moved to ssl
change the settings

Answer 2

https://debian.pro/1139 - that's exactly the story)

Answer 3

Have you written to Yandex technical support? She answered me within two days and pointed out all my jambs, and then checked again and confirmed that I corrected everything correctly.
With Google Apps, I also often had my own mail and alerts went to spam, following their recommendations did not help, only after setting up Reverse DNS, the inbox from the site mail (feedback and notification letters) became more or less normal.