Did anyone ever resolve this issue? I've spoken to Namecheap and they said just to enter 

admin._domainkey etc (no email address after) but it still won't verify! 

It's so frustrating as I moved this email to ZOHO from Namecheap as I thought their service was bad. Now it's even worse as my business isn't receiving its emails!

And the DKIM checker tool Zoho mentions also says their is something wrong with it, even now I am putting it in this new way!

Is it Zoho or Namecheap causing the issue? Should have just stayed there LOL