For security reasons, it is not possible to use the email address listed in the domain's WHOIS record for SSL certificate validation.

The approval email for SSL certificates can only be sent to one of the generic email addresses  listed below:

admin@yourdomain.com
administrator@yourdomain.com
hostmaster@yourdomain.com
webmaster@yourdomain.com
postmaster@yourdomain.com

The approval email address is to be chosen during the activation of your certificate.