This is undoubtedly a problem with our VLAN and firewall. In our building, which shares one internet connection and one firewall, we have 3 e-smith servers for 3 different entities. Everyone can send email anyware in the world, except to the other two machines in the building

It seems as if the firewall detects that the mail is coming from an address inside the building, and suspecting ip spoofing. blocks it. The Cisco switch defines the various Vlans, and is supposed to allow communication betweem the 3 mail servers, but not between the other machines.
It seems that the problem could be fixed by letting qmail know that mail for mhplace.org (for example) should be sent to 192.168.2.4, so that it doesn't go outside the firewall.
Suppsoing that I want to be able to send mail from mhplace.net to mhplace.org, I put the following entry in the hosts file of the mhplace.net e-smith server.
192.168.2.4 mail.mhplace.org
Is this correct place and entry? Any help in troubleshooting why mail frpm mhplace.net to mhplace.org always bounces would be appreciated.
Mike