This domain is not allowed to add in Zoho. Please contact support-as@zohocorp.com for further details

This domain is not allowed to add in Zoho. Please contact support-as@zohocorp.com for further details

After not using the domain rcclima.org.pe for some time, I'm trying to set up the free version of Zoho Mail. When I tried to validate my domain, rcclima.org.pe, I received the error message discussed in this thread:
"This domain is not allowed to be added to Zoho. Please contact support-as@zohocorp.com for further details."
I've read other threads on your community forum, and this is NOT a free domain. What's the problem?