Unknown Nokia Symbol.

[Describe]

My mums Nokia 6600 has shown a symbol the past couple of days that I simply can't understand. It's a weird shape that I haven't saw before and it's preventing her from sending texts (I'm unsure about calls). The symbol is a revolving text message envelope that turns around and changes into a pointy @ symbol. Theres nothing about it in the Nokia manual and my mums doing her nut. It's funny but nonetheless, any help is +REPPED.

[Coding]

Inbox/Outbux not full?

[Janet Snakehole]

perhaps check the service centre numbers are correct in the text msg settings?

[Describe]

She deletes all her messages when she reads them and she does the same with the outbox.

[Jack!]

I had that probelm with my nokia, turned out inbox/outbox was full

Edit: Read above post, the problem i had was low memory.