Amusing :) Although I have to admit that I am even less sure after using that site. There doesn't seem to be an indication that DKIM "FAIL" in red is a good or bad thing after it attempted to spoof a domain I own. I assume it's good?
Please read my blog here: https://www.uriports.com/blog/introduction-to-spf-dkim-and-d...
It will explain how SPF, DKIM, and DMARC work together to prevent spam.
This is the original submission where the link came from if it helps: