To send encrypted or digitally signed messages, you need to configure an encryption technology, either OpenPGP or S/MIME.
I wakken ad tazneḍ iznan i yettwawgelhen neɣ yettwazemlen s wudem umḍin, tesriḍ ad tsewleḍ tatiknulujit n uwgelhen, OpenPGP neɣ S/MIME.