Yes, it does, by design of the IMAP4 protocol. Let me try to simplify this because there is alot to know about the Lemonade Push Extrensions. It uses IMAP-IDLE technology which works in simple terms as follows: Flexmail opens a connection to an IMAP4 server and keeps the connection open, with an occasional heartbeat. When email is delivered to the mailserver it is pushed within seconds to your device. Both Z-Push and MS Exchange work basically the same (for the purpose of this discussion) from the client perspective with a heartbeat, but work differently from the back-end perspective. These two designs need to rely on their communication path being a webserver through ActiveSync. I forgot to mention, with WM6, Pocket Outlook supports IMAP-IDLE as well so for those device users, you don't need Flexmail. I know battery life is a frequently discussed topic in terms of 'Push' technology and here are my findings with an original Q WM5 device. I have found that my original black Q has the same battery life with any of the following. (1) Tests with Mail2Web 2003 Exchange Server (2) Tests with Z-Push (3) Tests with Flexmail.