How to correctly set the List-Unsubscribe header in emails?

Question

Email

Hello. When mailing, I send the List-Unsubscribe header in emails. I expect to see the unsubscribe button, which will be generated by the mail service itself, where the letter arrives.
I'm testing on three services: gmail.com, yandex.ru, mail.ru
As a result, the button appears only on Yandex. I assume that for other services there are some additional requirements that I could not find anywhere. Tell me, please, what could be the matter? Thanks in advance to all who responded.

Answer 1

Make sure the List-Unsubscribe is built according to the standard and in the case of mailto: you are using an authorized domain (i.e. you are not using, for example, a free mail domain in mailto).