I checked and only the www version of your domain works fine, so it seems like the DNS records for your domain were corrupted. Can you please remove and re-add the domain from the “Addon Domains” section of the Control Panel, then upload your website files on yourdomain/htdocs with a FTP client, where yourdomain can be replaced with your domain, and after that try to set up the Zoho’s MX and SPF records? Like so, I think it would fix the problem.