Well, I'm pretty sure that no engine is capable of reading anything. I'm guessing that you're asking about reading text/email messages over bluetooth, and in that case the answer is "Sometimes". Depending upon your device, this function can be anywhere from incompatible to flaky. Safe money says don't count on it, though I'd be interested to hear of anyone who has been using this service successfully and reliably.
It's not a feature of Entune in the base PiP. I thought there is email/message capability in the advanced model, those owners may be able to clarify.
Advanced will read text messages with a compatible device. Toyota's compatibility chart indicates the potential for reading SMS text, but not email.
The base PiP Entune WILL read texts/SMS/iMessage (at least they do from my iPhone, but I would assume Android is even better in this regard). I just cant respond to text messages. If I'm stopped, the system will not read the messages to me. But if I'm moving, it will.
What model iPhone and iOS? I have iPhone 5 with iOS 7.1.1 and I've never had it read them. How do you get it to do it?
Depends on the phone. Toyota has a compatibility list: http://www.toyota.com/content/entune/pdf/EntunePhoneCompatibilityList.pdf Entune does read text messages from my Samsung Galaxy Light. So far it doesn't seem to alert me to them, but that's ok because I can hear the alert from the phone's speaker. (I'm pretty sure with my HTC Sensation Entune actually alerted me, even though Entune didn't support reading the messages on that phone.) Note that my car isn't a PiP, although from the chart it looks like it should be the same?