How to set up your mail server so that emails do not end up in spam?

Question

Mail server

I decided to raise my mail server, but there was a problem. Gmail shoves all emails from my mailer into spam. Moreover, Yandex seems to have begun to define it as Spam. There are two mailers in the .LIFE and .LV zones.
What I have:
PTR record specified.
there is a TXT record v=spf1 a mx ~all
there is an MX record with priority 10 for the mail address. domain.name .

Answer 1

quite recently there was the same problem, first you need to configure DKIM, and then see my question with answers: What could be the problem with DKIM?