The Mailbox and the emails are deleted from the device but remain on the server.
Depending on the device the tasks, calendar and contact items remain on the device. Note: In the Symbian^3 devices also tasks, calendar and contact items will be removed, when removing Mail for Exchange mailbox.
All security policies were enforced to the device will remain, for example the device lock. To remove the device lock and all security policies installed, a factory restore of the device or hard reset (*#7370#) must be performed.
Note: Hard reset (*#7370#) will be formatted the internal mass memory E: in the Symbian^3 devices (e.g. Nokia N8-00, E7-00, E6-00 and X7-00). It is therefore important that you back up all your data from the E: mass memory before resetting the device. Use Nokia Suite to back up the contents to your PC.