Mail to Hotmail still being blocked but ONLY from Zoho

I've sent email to the blocked address from a Gmail account and the emails are delivered OK, it is only the zoho emails that get blocked.

I have been sending and receiving emails from the hotmail addresses for years. Why has this just started to happen? Is anyone looking into this problem.

I'd be really sad to have to leave Zoho over this as I really like the service that you offer, but honestly what alternative is there when you are not able to send email to your friends?

I came to Zoho to get away from Gmail and I know I am not alone in that. But for all their faults Gmail is always there.

I am not the only one who is having this problem but I suspect that if you don't see any responses it is because those people have moved already, rather than the problem having been solved.