Here is a weird problem that we're having...
We have 2003 x64 server that people use as a terminal server, everyone has non-cached Outlook 2003 profile, we dont have our own Exchange and are using outsourced one via HTTP.
Everything worked perfectly for quite a while - 6 months at least. Then one day - we started getting Exchange is unavailable message occasionally. Message gives options to Retry, Work Offline or Cancel - Retry never works. The only way around is to keep closing the Outlook and starting again then eventually it will let you login.
Sometimes it lets you login right away without any problems though.
Im my investigation i noticed that when i create Outlook profile in an account of brand new user or a user who wasn't setup with Outlook before - it works perfectly, just like it worked before the whole thing started.
If i delete existing account profile, create a new one and configure Outlook again - it works crappy as it was with old profile.
Most have Outlook setup on their local machines and no one experiences any problems there
Let me know what you think