Zoho mail addresses considered invalid/dangerous by multiple companies

Zoho mail addresses considered invalid/dangerous by multiple companies

For at least the third time, I am unable to use my personal Zoho mail account at a major company.

Panera Bread/restaurant and Zazzle will not let me register for accounts using my Zoho email address, considering them invalid. I suspect several other registrations I've had problems with (and simply abandoned) were for the same reason.

Recently I had nothing but headaches ordering a computer from HP (Hewlett-Packard) -- I was able to put in my email, but the order was rejected (but charged to my credit card) ONLY because HP considers Zoho a domain that is used too often by criminals and hackers! It took me many hours to straighten this out, ultimately by providing them with a different email address. They refused to accept Zoho despite my explaining the situation to 7 customer service reps.

I switched all my personal shopping, newsletter registrations, etc. to Zoho when Yahoo mail began it's decline. If this issue isn't resolved somehow I see that I will have to move again.