http://mosquitto.org/ is the software that I am talking about. It does not have the ability to poll gmail, or other email services built in. MQTT is a pub/sub system where you can subscribe to topics from the server. The device then receives updates whenever the server posts a new message in one of the topics. My plan was to have the device (n900) subscribe to topics based on what types of notifications it wants to receive from the server (email, google voice, etc). The server then receives emails when it needs to notify the n900 (for google voice sms messages), or it polls a server to determine when to push the information to the device (for facebook messages, etc). Email can either be handled by forwarding your email to the server (an option in gmail), or by polling the server for new messages). I played around with creating an imap4 client on the server that could check for new messages, and notify the n900, but it was a lot harder than I thought (noticing that there is a new email is difficult without storing all of the email so you can tell when there is a new one), so this would require some more work.