PEC means Posta Email Certificata, it’s a certificated e-mail service. A certificated e-mail is comparable to a registered letter with reply, where both sender and recipient use the certificated e-mail service. The outbound e-mail is encrypted and is secure from abuse by third parties. It can be read on both computers and mobile devices.
Since 2009 every company in Italy is obbliged to possess a PEC-address. Registration to the national commercial register is no longer possible otherwise.