Mail Won't Leave the Server

All our CGI's and notifications send mails to the domain "hindu.org" and the MX records for hindu.org are all pointed to Postini and Google Mail servers.

I created a virtual server "wiki.hindu.org" and when I did I disabled mail for this domain. But, if another cgi on a different virtual server tries to send, e.g. from Hinduismtoday.com "subscribe@hindu.org" the mail doesn't leave the box. Instead it thinks that it should try to be sent to "hindu.org" on the same machine, can't find any mail box or user for "subscribe@hindu.org" and bounces.

Any ideas on a solution from within VirtualMin/WebMin GUI? Or should I have ServePath look into it (our host support team)