Zaccardo's agent confirmed the deal as he left Milan's headquarters, saying 'it is a great opportunity for Zaccardo and a real high point in his career. He'll have the same contract he had at Parma, he hasn't given up on anything'.
Zaccardo will reportedly have a medical at Milan on Friday. Mesbah is currently at the African Cup of Nations with Algeria.
The 31-year-old Zaccardo was a member of Italy's FIFA World Cup-winning squad in 2006.