Is there an open standard for push email? Should there be one?
IMAP IDLE. Gmail supports it, but iOS's Mail app doesn't, that's why you have to setup Gmail as an Exchange account to have push. Supposedly, IDLE support is left out because Jobs said it's a "power hog."
No, there isn't an open standard.
IMAP Idle isn't technically "push" - hence why it's a "power hog".
It just lets the email client stay connected to the server in an "idle" state, until a message is ready to be downloaded.
There's not really anything like Exchange ActiveSync - and that's why it's always been so popular.
It's usually very easy to configure
It offers email, Contacts and Calendar with just one configuration
It's generally very reliable
It has push
Since Microsoft started licencing the patents that go with it, other companies can offer it in their products - on both sides of the equation: device manufacturers like Apple, email providers like Google.
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From the sound of the Google blog post, if you move to a new iOS device, you will lose Exchange GMail. I assume they are using the device ID to determine if you have changed devices.
To clarify this, the "Device ID" used by Exchange ActiveSync is simply:
"Appl" followed by your iPhone serial number (NOT the IMEI).
That
should mean that:
-If you restore your device, Google Sync should continue to work
-If you get a new device (an upgrade or a replacement) then Google Sync will NOT work