SMS is used to send tiny chunks of text, and SMTP can be used to send message content in HTML format and rich text in addition to plaintext. I haven't worked much with rich text format, but HTML format for sure would be relatively impractical via SMS (XML adds a lot of characters, so you would have a lot of little chunks to send if you wanted to send HTML over SMS).
I agree with that. I don't mean that I want to send my email messages visa SMS. I mean that I want all my messages sent/received and read in one messaging client, whether they are transported via SMS, SMTP, etc. If the HTML message should go via SMTP, I expect my software to deal with that. I want the content; the transport is an obscure detail for developers to worry about (speaking as a typical end user).
You're asking for a magic genie content router that does not exist. It does not exist because its a hard problem. Not only would you need to interoperate with open standards, you'd have to attempt to integrate with unwilling participants (Facebook, Google Hangouts). Are you prepared for that level of pain?
You also have to consider that facebook already do this. They tried to wrap up email, messages and an SMS replacement on your phone into a single package where they own the whole thing.
I look at iMessage and I think it works pretty perfectly, SMS when no internet or to a non apple user, iMessage whenever possible. What I want is for whatsapp (and I suppose facebook and plausibly email) to do the same all in my single messenger application.
But. Ignoring the need to get the tech owners to consent to this new "trillian", I'd also have to trust the app itself. Good luck making money on that.
Well, if you want that, then you should support open protocols. The business goal of twitter, facebook, etc. is to lock you into their communication system, so if you expect developers to integrate those, you really expect them to invest into integrating with those who want to destroy the open ecosystem that they rely on and who will do whatever they can to hinder the integration.
