[Garfield123]

If I understand correctly, imap idle clients mantain a connection to the imap mail server, which notifies the client immediately of any new mail. Blackberrys, instead, receive some sort of 'hidden' sms which triggers them to connect to the server and retrieve emails as they arrive.

Is this correct? Does this mean that, all else being equal, imap idle solutions consumore more power, whereas Blackberrys have the potential of a longer battery life? Or is the matter much more complicated than I thought?

[hrbuckley]

Not sure how RIM implements PUSH, but yes that is essentially true. In order to keep a socket open so as to be notified by the IMAP IDLE protocol the TCP protocol must periodically send keepalive packets. This alone will consume power. There is also the issue of the device moving out of coverage breaking the connection which must then be re-established.

[Berry One]

Blackberry supports IMAP IDLE. It is done through their NOC. Blackberry NOC opens IMAP IDLE connections to IMAP servers, so no battery drain on blackberry and no risk for connection to go out of coverage.

When NOC receives messages to your device from IMAP IDLE connection, they are pushed to your blackberry using power efficient and reliable blackberry push protocol.

With IMAP IDLE and blackberry device you are getting best of both.