Can't view squirrelmail outside subnet
 

I've setup a mail server on Red Hat 9. It already had Squirrelmail installed and it works on the local LAN, but on a different subnet or remote connection I can't view it (Page cannot be displayed). The web server works fine remotely. I know the alias is redirecting to a local folder as the FQDN changes to just the hostname. How do I change the alias to make it viewable outside the local network?

Tried
Alias /webmail /usr/share/squirrelmail
Alias /webmail "/usr/share/squirrelmail"

Thanks,
gNuB