"E.T., you’ve got mail" is a national competition organized by the Italian National Institute for Astrophysics for primary and secondary school students. Inspired by the 1974 Arecibo message, students design binary-encoded pictograms to be transmitted via radio antenna toward stars hosting potentially habitable exoplanets. Two editions were held (2022, 2026), with winning messages broadcast from professional space facilities, the ASI Space Center in Matera and Telespazio's Lario Space Center, toward exoplanet targets. The activity integrates astronomy, mathematics, coding, and critical thinking, fostering computational skills and interdisciplinary reasoning. Students engage with topics ranging from binary encoding to scientific and philosophical challenges of interstellar communication.