Now you no longer need to worry if someone else would read your important or personal messages in your phones because here is a solution for you on how to hide private messages in Symbian devices. All the thing you need is an application called MumSMS.
Install this application and launch it.
For the first time, you will be prompted to enter password. Enter your desired password and reenter the same password for verification.
Now you ready to hide your messages, go to inbox or anywhere your message located, mark all the messages that you want to hide, press Option and press Hide.
If you wish to unhide the messages, mark those messages, press Option and press Visible.