This maybe something you are looking for? I left out the email transcription part from handsfree.ly because the transcriptions are so bad, it wasnt worth the effort....
Hi,
I released a free android app (handsfree.ly) and a paid $1.99 version (GMail handsfree.ly) that essentially do what you are asking. My tech stack focuses on the speech recognition part (names anyone..Goog chokes on my name eg) and the TTS part. I built the GMail reader app to showcase this tech stack.
You can:
-Listen to all your unread emails (just subject,sender,date)
-Listen to body, Reply, Compose, Pay (via PayPal)
It is very very secure because you never hand out your gmail password to handsfree.ly (you authorize via google and can revoke this auth anytime you wish). Just setup your a/c at handsfree.ly (thats the url btw), download the app and happy listening....
-Sanjay