Hi there! I hope I'm putting this in the correct section...

Recently I though of the idea of "building" something for me.

As you may guess for the title, I want to create an email client and I know there are a lot nowadays but either because of limitations or graphic design I want to do one by my own and for myself. And maybe in the future I would release it as an app for the web, desktop and/or mobile.

What I can't decide is what language(s) and/or framework(s) I should use to create such a thing, so... If anyone could give me suggestions I would be much aprecciated.

I can see where folk get lost on such an endeavor. To me that would be no less than 3 apps. But one of them might be used by all 3 platforms. If you created an email client on a web page then you hit all platforms with one app.

I see from your past posts you know a little about web site creation so maybe that's what's first.

On a similar approach of @rpoffitt, you could built it with NodeJS and just make an wrapper for each plataform. This way you can code almost all of it in JavaScript/HTML/CSS and with little effort you can have an app for each plataform.

Basically your app would be an site inside an closed browser.

Brackets and Atom editors are made this way.

It's a great way to make open source projects because JavaScript is only getting more famous and basically any Web Developer can tweak/improve the app.