I don't know if it'll work like this, but I'd love to see it like this, at least at the UFO stage.
1. Arrive at the planet, and play the CEOTTK game to establish a base language
2. Once this is over, you can communicate, but only in very simple terms, and when you send the messag,e you get to see the lights and hear the music while it's being sent and recieved
3. You can send messages to them that are more or less messages in a can (We come in peace, Take me to your leader, My other UFO is an X-Wing, etc.)
As such, the terms for communication would be poor at first, but you'd adapt and learn their language. I wish you could send personalized messages but I doubt it'd happen considering how complex it'd have to be.