Windows Mobile 6 is the first version of Windows Mobile to include push email support without setting up an Exchange server. Of course, it only works with Hotmail, but it's a start.

Once you have a Hotmail account, all you have to do is:

1. Open Windows Live on your mobile device.
2. Enter your Live information and set your device to use Live services including Messenger, Mail, and Contacts.
3. Click on menu and selection options.
4. Select Sync Schedule
5. Under frequency, select "as items arrive."

Now every time an email is sent to your Hotmail account, a copy will be sent to your Windows Mobile device. You can even configure your phone or PDA to work with both Hotmail and an Exchange server, allowing you to receive push email from two separate accounts.

[via MobileViews]