Mail goes to Spam folder despte custom sorting rule

[ShadowWisp]

Recently QQ mail about thread updates has started to be sorted to spam folder despite me specifically sending QQ mail into "SV/SB/QQ" Folder in my mail.
Reasons as to why mail provider dos that are:
~Sender did not pass SPF check
~the PTR record on the sender's domain is configured incorrectly
Or if we go in Russian language because i use Yandex,

Это письмо попало в папку «Спам» по следующим причинам:
отправитель не прошел проверку spf
некорректно настроена ptr-запись на домене отправителя

It does not send ALL of QQ mail to spam, but the pattern is not clear

 

[TheMidnightRook]

Emails have had issues for years.