Does the ticket I have received on-line constitute my ticket for the embark?

Tickets attached to the e-mail confirming the booking, are not valid for the embark; in order to get on board, it is necessary to have the boarding card which will be released by our staff at our ticket office, inside the departure port.
For departures from/to Sardinia, for which it is available the fast check-in, it is just necessary showing the ticket to our staff, at the moment of the embark.