How do you get rid of the flashing envelope symbol from the top of the Nokia X6 screen it's none of the symbols from the instruction manual so I don't know what it is or how to get rid of it?

How do you get rid of the flashing envelope symbol from the top of the Nokia X6 screen it's none of the symbols from the instruction manual so I don't know what it is or how to get rid of it?
It is probably telling you you have an unread text message, go into your inbox and ensure all messages are read if one is not read open it. This should get rid of the icon.