configure zimbra for valid domain

Dear sir,

I have installed zimbra in Ubuntu.
I have got a 2 valid domains.

1. www.consulting .com

I have created a subdomain, web.consulting.com & configured in zimbra server with bind dns. its working fine.

2. I have got another domain
Default Index Page

I have got 10 mail accounts in it.

Now if i have to configure this domain in my zimbra server, so that i can downlaod all mails from external accounts to my zimbra server & send the mails only through zimbra server.