This genuinely confuses me. I have used every dmarc/dkim test out there
that I can find, without paying money, and every one of them I pass.
When I send email to my gmail account it passes. 

But when I send email to this group, I get half a dozen failures and
complaints... what gives? 

PS google dislikes your email,  
"Be careful with this message 
Gmail could not verify that it actually came from codezilla.xyz [1].
Avoid clicking links, downloading attachments, or replying with personal
information." 

Links:
------
[1] http://codezilla.xyz