SMS delivery report

Yes,it is introduced in a firware version,don't know which one but you have to set it on every new message.Search the forum for more info or update your device to the latest firmware.

what was the gsm code you can put before a number to get the delivery report?

Here in the UK, if you type RPT at the start of your message you get a delivery report sent back to you. But as this is the UK, and we are a mad country, who knows if it will work anywhere else 😊

there's a gsm code # something something # or something like that,

Actually, try a ! (exclamation mark) as the first character in the message. It works using 'Pronto' on the Isle of Man, UK with a P800. Came across this by accident.