Not able to sign-up for Zoho Campaign

Not able to sign-up for Zoho Campaign

Trying to sign-up for Zoho Campaign, Getting an error message which says - " Email address already registered" ....Have tried with my existing Zohomail mail id and also using my Gmail mail id. Same error.

Will be great if we have seamless signup using my existing Zoho credentials.

Let me know how to resolve the signup issue.

Thanks and regards,
Siva