Need to send email from your web app? Don't want to use Gmail because of limits?
Okay I'm not about to break into a marketing campaign, because I just found the website, but it looks like AuthSMTP solves the problem.
I literally just discovered this place, but you can send up to 1000 emails a month (100MB data), for $24USD a year. Not too bad.
You can send with your own from address, etc, etc, and all the things you'd expect (at first glance anyway).
If I end up having the need to pump out lots of email, I'll definitely give it a go.