We have Exchange Server 2007 using our domain ddd.com.

We created an isolated network with a firewall/gateway and installed a DC and Exchange Server 2010 using a demo/test domain (ddd.loc).

We opened all the needed ports in the firewall (10.10.2.88) to the Exchange Server 2010.

In our main Domain Controller (10.10.2.3) we defined the domain ddd.loc with IP 10.10.2.88 (firewalls). We also we defined MX records to the same IP (10.10.2.88)

We did that so when we send email from my email [email protected] it will go to the Exchange Server 2010.

Anyways, all the pings test from to any servers are OK.

But we are not able to send or receive emails. Between these Exchange Servers we can not send any email from the 2010 to any email in general (emails are pending).

Also, in Exchange 2007 we are getting error #550 5.1.1 RESOLVER.ADR.RecipNotFound; not found ##