Hi pals

I am new to zimbra. I want to block all outgoing mails to all domain but except particular one.

ex: i have two mail server with two domains.

1) mail.knowlede.com
2) email.knowledge.in (zimbra)

both are working in public ips.

now i want to send emails from 2) to 1) only but won't other domains.

is it possible to restrict to particular domain?