The best solution at the cheapest price everExample: YourCompany@kelipec.it
Certify the third level domain with your company nameExample: email@example.com
Certify the whole domain with your company nameExample: firstname.lastname@example.org
The Certified E-mail (PEC) is a specific kind of e-mail as legally valid as a registered mail with return receipt and it's generally used in the administrative and commercial fields.
When you send a PEC the provider in charge of its management sends you a receipt, as proof of the operation including the date and hour of delivery. At the same time, the provider receiving the e-mail, after dropping it in the receiver's mailbox, will send you a receipt as proof of the reception, containing the date and hour of the operation.