Spam Control - How to white list a domain?

Spam Control - How to white list a domain?

I'm a web developer and frequently need to send test emails from my applications to my personal email address, which is hosted at Zoho. Despite adding the sending domain to the spam control white list (Control Panel -> Spam Control -> White List -> Domain List), I continually have to get into my spam folder and unflag emails from that domain so that Zoho will usually send them to my inbox normally. Once I unflag a message, Zoho will deliver from that domain for the rest of the day without problems but I'll usually have to repeat the procedure the next day.

How can I convince Zoho Mail that ANY mail from a particular domain is always to be delivered normally, despite whether or not Zoho Mail thinks it's spam?