"The domain which you have entered belongs to a different deployment/region" problem

"The domain which you have entered belongs to a different deployment/region" problem

Hello

i have a problem with Zoho Mail configuration. On one hand when registering the domain the  "The domain which you have entered belongs to a different deployment/region" message is displayed. I created an account but when registering the domain www.MRXM.org the "it already exists" message appears. 

Hope you can help me,

Julo