Google recently killed their native app for the Blackberry platform advising users to switch to web app or use the native email client on the device.
The company seems to be following a similar policy now for the Symbian platform. The Java app available for the Symbian platform is no longer promoted on their mobile section.
Users are stuck with a basic HTML based web edition to check their emails if they are not using the inbuilt email client on their devices.
Google of course has a native app for the Android platform and they just recently launched a hybrid app for the iOS devices.
The good thing is that Google offers free POP and IMAP support on Gmail so users can still use any third party service to access them. Gmail specific features however are restricted to the official apps and the advanced web interface accessible from webkit based mobile browsers.