Why cannot you send the approver email to my personal mail id?

Please note that the certificate authority needs an explicit approval from a domain owner to issue an SSL certificate. Since only you/any authorized person in your company will have access to setup an email address associated with the domain or email forwarding for any one of the generic @domainname.com email addresses, the approver email is sent to the @domainname.com address and cannot be sent to any personal mail id as a security measure. The only exception is the email address listed and publicly visible in Whois.