[PLUG] What should I do?

[Michael C. Robinson]

Jul 10 16:23:12 web postfix/trivial-rewrite[23689]: warning: do not list
domain robinson-west.com in BOTH virtual_alias_domains and relay_domains

The robinson-west.com domain internally is a local area address.  
>From the Internet if you try to resolve this, you'll get a global
address.  I've tried putting in an IP address, but I don't think that
will work here.

Do I need to add another domain to my internal network?  If so, what
should I add?  How about a subdomain?