Okay, this is a partial answer to your question. You don't need an email server program to use UBB's email. Set up your SMTP server as described here:
Setting up SMTP Email . Then in UBB control panel in general settings, tell it to use SMTP and enter the internal IP address of your server = 192.168.0.20 for example.
This way, UBB will use your SMTP relay that is built into IIS. However, without an email pop server, you will have to collect your email in your drop server or your can have your email forwarded to an alternate email address.
What I've described is how I run my website. It's not optimal, but it works.