@mycoo368 I have the exact same issue with DKIM, I figured out that DirectAdmin puts tabs and newlines into the DKIM record which makes it invalid.
I don't think there is any way to fix this, however looking through my personal email, I see that many sites do not use DKIM and yet are successfully delivered to inbox. I therefore have disabled DKIM, now I think it is up to the sender reputability that decides whether my emails are marked as spam or not: for clients who have replied in the past to my emails they are now receiving it in inbox, but for new clients they are still getting marked as spam.
This post has the details of the DKIM problem: [
https://x10hosting.com/community/threads/invalid-dkim-due-to-tabs-inserted.207023/ ]