I just had to setup BIS for a customer and had a few problems. Proved to be a valuable learning experience.
When setting up BIS there is basically one error it will give, "Cannot connect to email server or invalid server name"
This error, however, can mean several different things.
Invalid address: check your address, it's generally https://mail.domain.com/exchange (for 2003) or /owa for exchange 2007.
Invalid logon name: it is generally DOMAIN\UserName
Invalid Mailbox name: this one is tricky... It's generally the same as user name, not necessarily what you find in System Manager. It has to be exact match to active directory. This setting is what got me today.
Email address must match the server address. So if you try to use karl@domain111.com when the server address is https://mail.domain222.com; it will fail.
Oh, and last but not least, invalid password.
