[leahrev]

Thanks so much for your post! I haven't typically had a chance to take the time to do many traceroutes etc while these problems occured since many people were scrambling and just wanted the problem resolved ASAP. So I'm thinking about scheduling a maintenance window during which I'll force failover from fw2 to fw1 so that I can work on the OWA problem without people breathing down my neck.

As for the NAT issue - the NATs were in use for our email servers and when it started happening our email admin advised that all outbound mail destined for outside our network was queuing at the firewall (all inbound mail from outside companies were successfully delivered as well as emails sent from within the company to other addresses inside the company). In your post, you mentioned that it's possible that we have proxy ARP configured for the NAT on fw1 but not fw2. Pardon my ignorance, but where on the GUI and/or CLI can I check for this?

I think I'll hold off on building a second machine for now and continue troubleshooting the one we have in hopes that we can get the problem fixed.

Thanks for all your help!
Regards, Leah