I've set up OWA on a Server 2003 Standard box. I can access OWA from the network using either servername/exchange or publicip/exchange. External users who type publicip/exchange get a "page not found" response, much less a login box. I've forwarded port 80 in the firewall to the IIS server, and I've double-checked everything against other OWA sites I've set up and I can't find the problem. We've got dynamic DNS set up, but it doesn't matter whether the DDNS name is used or the actual public IP address - if you're outside the network you can't access it. I think it's a permissions problem but I'm stumped.
Thanks in advance.