I have searched and searched to no avail, but I did find a few alternatives.

- MOrange (Nothing else needed beside register & download app)
MOrange provides Free push-email, works with Hotmail, Gmail, Yahoo, POP3, & IMAP4. The app also includes some other cool features. The only draw back is that the free account will only push you the first 2KB of each message, and you cannot access/send attachments. You will have to minimize the application(leave it running) for it to receive "instant" push emails.

- Consilient (Nothing else needed beside register & download app)
Consilient is just like MOrange, but it is doesn't have the extra features, just plain simple push email. The advantage is that, there is no size limit on Consilient, you can recieve/send attachments. The only drawback is that it will post a text ad on the bottom of your sent messages. (i.e. Push email from Consilient, get it today!) You also need to leave this app running in the background to receive instant push email.

Also tried Flurry, I think their GUI sucks. There are few others that requires you to pay a little fee each month to use, such as MovaMail, which I didn't test out.

Also remember, AT&T's mobile email have the SMS new email notification, those SMS are free. But if you use 3rd party app with SMS noticifaction, those SMS are not.