Get Gmail as Push Email on Sony P990i
While I have moved on from P990i which is now in safe hands of my dear wife, I remember doing some good amount of web searching and still had no idea how to set up push-mail on P990i.
I then thought I will configure a mail anyway and to my surprise the device is capable of enabling push-mail on it`s own as I found while fiddling along. Anyway I have configured push-mail for wifey dear and she was mighty impressed. 
The steps I followed are as below: