- You need to create an account at http://email.nokia.com and install the application by sending yourself a SMS from your account.
- Make sure there is a packet data connection on your cellphone, it doesn’t have to be active. Nokia Messaging just needs a packet data connection to continue the setup.
More info http://betalabs.nokia.com/betas/view/nokia-messaging-for-s60-5th-edition and http://thenokiaguide.com/2009/08/12/problem-solved-nokia-messaging-requires-packet-data-connection-for-setup/