Problems with OWA Authentication

I’m sure that this question has been asked before, but I have been trying to get OWA working in my company. We’re running WNT4 Server SP6, and IIS4.0. I can access the server via the browser, but when I try to open a message from the inbox, I haverelogon before the message appears. Additionally I would like to remove the need for the domain\username from the logon box as this would confuse the user. Once I have these issues sorted then I would like to go down the SSL route, which is beyondme. If anyone has any advice or has been down this road and knows of the pitfalls, then please let me know.