OWA stops working from external network connection
I am running two servers, an Internet Security and Acceleration (ISA) 2000 server with Internet Information Services (IIS) and an Exchange 2000 server. Recently, my Outlook Web Access (OWA) stopped working. I have checked all the settings on my Exchange server and reset OWA through the ISA Management Console with no luck. I can access OWA internally, but not externally. If I connect to the ISA server through the VPN, OWA works, but it does not work from an outside network connection. Do I need a Microsoft update on one of my servers?
There are many settings within ISA Server that could be causing this problem. You mentioned that you reset OWA; I'll assume that this means that you ran the wizard to publish Outlook Web Access. This wizard is the quickest and easiest way to restore the settings that you need.
However, if the ISA Server is not the problem, have you verified that your Domain Name System (DNS) host record still points to the correct IP address of your network?
For example, if you use https://mail.yourdomain.com/exchange as your OWA URL, make certain that mail.yourdomain.com resolves to the public IP address of your network (typically the firewall).
Do you have comments on this Ask the Expert Q&A? Let us know.
Related information from SearchExchange.com:
Expert Advice: Enhance OWA logon security using Microsoft ISA Server
Tutorial: A primer on DNS and MX records
Learning Center: Troubleshooting OWA
FAQ: Outlook Web Access
Reference Center: Outlook Web Access tips and resources
This was first published in October 2007