From an old Mack Reynolds short story. The recipient is receiving a message from an alien space station, but doesn't have the alien's message machine, just a decoder.

    Seal Ready
    Stamp-Emblem Ready
    Number One Paper
    Strike: Embossing Master Emblem Number Two
    **** Border

    Begin Message
    From: Commander Space Fortress Ironclaw�

    To: Commander Unidentified Damaged Warship

    Sir:
    Your ****-signal received and acknowledged herewith. This is the correct
    signal for the ****. However, we require the following information:
    1) Who are you?
    2) What is the name of your ship?
    3) What are the circumstances surrounding the **** of your ship?
    This information must be forwarded at once, or we must refuse entry.
    Stand off while replying.

    Cordial claw-claspings,
    Gratz Ialwo,
    Commander Space Fortress Ironclaw 

    Fold Message and Glue Shut
    Stick Seal
    Stamp Great Claw on Front
    Eject