Looks like you have some nice features here. This is not something to laugh at, at all.

I could see using something like this for a customer support email list.

Pricing is an issue, though. If I actually had a running business that was doing its customer support over email, the amount you're asking would be no problem. But I could also see just using it personally. For that, however, the price is too high by a factor of 10, maybe 20. (Compare Evernote, for example, at $5/month.)

Have you considered offering a free plan for personal use? This would give you an opportunity to demonstrate value and build a user base. At the prices you're asking, you would need only a small fraction of users to convert to the paid plans to make money.

You have some good ideas here and I think you're attacking a real problem, but you are in a space where it's going to be very difficult to get noticed. It's not going to be easy to overcome that.