cant use mail API

cant use mail API

I have generate Auth token from https://accounts.zoho.com/apiauthtoken/nb/create?SCOPE=ZohoMail/ZohoMailApi&EMAIL_ID=Zoho Mail Username or Email ID&PASSWORD=Your Zoho Mail Password
and get the token

but when i use that token on  http://mail.zoho.com/api/organization/ with header Authorization : Zoho-authtoken <this my token>
I got following error
{"data":{"errorCode":"URL_RULE_NOT_CONFIGURED"},"status":{"code":404,"description":"Invalid Input"}}

is there any way to use mail API? I am use free plan mail service