[starbeast]

>I am dismissing those that reject proprietary software on principle.

That dismissal presumably includes both Stallman and the Debian project. I would not dismiss them all that lightly.

>I also made it clear that we would open source our software if we could find a business model that would work for us.

You are making a nice email client. The service of rock solid business email management would presumably be the obvious model to start with. There are more people willing to spend money on that than there are people willing to buy a better email client.