Transferring Outside Email from another Hosted Company to internal email server

[cnstetson]

So I'm trying to set-up a Zentyal email server. I have the email server completed and set-up and all DNS records set-up my question is the domain. My internal domain is currently (Using example) "test.lan". I have outside email hosted by another company and I want to bring it in house (ex:) test.com. So in exchange you add "accepted domains" on a exchange server. How to do you do that in zentyal.

Current external email (Example) Hosted by another company.
* john@test.com

Setting up Internal email server on internal network which is currently "test.lan".
Internal email account is now:
*john@test.lan



How do I get (not DNS related, that is all set-up) the domain @test.com on my internal zentyal server?