I have separate my website and email hosting. I use yandex smail service for email hosting. Everytime I send and email to an address, I get no dkim authentication issue even though, I have configured spf, dkim and dmarc in my dns zone.
For example, if I send someone an email and they have a gmail account, they will receive my email with a question mark instead of an unknown avatar and when they hover the avatar it will say: "Gmail couldn't verify that [my domain] actually sent this message (and not a spammer). "