I would use it if I could host it on my own server and run it on top of Gmail using IMAP and Postgres as a cache.
I could pay 30-50$ for it, but I think this would be even more awesome as an OpenSource solution, your product rocks compared to other alternatives as SquirrelMail, and you can always offer a hosted plan as a way to make money from it.
> Attempts a comparative analysis of experience with different tools both as a "developer" and a "designer" without explaining the significance of either term; what's a "Photoshop CS5 Developer" or a "Textmate Designer"?
It's an interpretation error, the bars indicate expertise and frequency of use (shown below).
https://roadrunner.dev/