At Milan Malpensa airport, passengers connecting between two international flights can usually stay in the transit area without going through immigration.
The airport has 4 terminals or concourses (Terminal 1 (A, Schengen), Terminal 1 (B, non-Schengen), Terminal 1 (C, Schengen long-haul), Terminal 2). They are not connected after security: changing means going through security again.