If you are looking for Push email solution for your Android Smartphone, then TouchDown is the perfect application for you. It provides MS Exchange ActiveSync support and synchronization features allowing users to easily configure and use their enterprise email accounts on their Android Smartphones. The application is currently in beta phase but registered users will get a free upgrade to the next release of the application. It is available in Android Market for $29.99.

Here is the feature list:

Compose and send Email
Reply to, Reply All and Forward your email
Delete Email messages
Move email between folders (yes, email folders are supported)
Add, Delete or Edit existing contacts when you are on the move.
The changes to your contacts will be automatically updated to your Exchange account.
View your daily/weekly/monthly calendar
Create appointments
Appointment notifications
Customizable alerts
Database on SD Card - saves phone memory

Via: Into Mobile