Yes, there are many great, excellent, fantastic mail apps.
In no particular order:
Boxer, Cloud Magic, Mail Wise, K9 Mail, TypeMail, Outlook, Gmail...
And I'm sure I'm missing another dozen or two.
You're giving the competition toooo much credit. Several of those mentioned have security concerns, missing features, etc. And yes, those listed and others not mentioned may have some particular features AquaMail does not.
But IMHO AquaMail has unique features too, like the Smart Folder, the most customization options, and the most useful options, and the cleanest, most intuitive UI (well, maybe with the exception of finding some submenus). It's fast, stable and reliable. All that in a surprisingly small file package.
Of course I'm not saying anything everyone here doesn't know. I'm just repeating it here as a reminder to Mr. Vasilyev not to lose sight of what has already been accomplished with AquaMail. Or lose sight of what can still be done.
I'm no developer. I can't code worth squat. But I've used Linux for nearly 15 years and Android since v1.0, when I got one of the very first G1 units. I've tried a lot of software. A lot of email clients - Gmail, MyMail, K-9, Maildroid, Enhanced Email, BlueMail etc, etc. Probably 15 or so by now. AquaMail wins, the best general-purpose client yet.
And when I recommend AquaMail, which is often, I like to add that not only is it an excellent email client, it's one of the best apps of any kind for Android.
So keep up the good work! It is appreciated!
Android since v1.0. Linux user since 2001.