You cannot claim a SuperEnalotto prize from abroad; instead, you have to claim your prize in person from either a ticket retailer in Italy, one of the lottery operator's regional offices, or one of the dedicated payment centres.
SuperEnalotto jackpots grow very high because there is no cap on them and no roll down of jackpots. The lottery is also appealing to players because winnings are taxed at only 20% on the excess over 500 euros, with tax withheld at the time of payout and jackpot winners have the option for a lump sum or annuity payment.