I use Flurry on my pearl and it works splendidly. It supports multiple accounts and although it doesn't incorporate an alert for mail in the program, you go to the flurry
website and set up SMS alerting to new emails. A long way from push but is a nice app for being a free service. You need to sign up for the service at the Flurry website.
The flurry forums site contain links to the desktop download of the java files for installing from you micro sd card. Flurry Forum :: View topic - NEW FLURRY RELEASE: Ver. 01.02.18
I just downloaded and tried out LogicMail, this is very buggy, I get an error and it won't connect. Also looking over the app, I can honestly say Flurry is Robust in comparison. Just my 2 cents worth.