Path of Exile is a free online-only action role-playing game set in the dark fantasy world of Wraeclast.
YouTube - The REAL "Diablo 3" : "Path Of Exile" .:.Vatolicious Gaming.:.
The (currently) full list of outgoing ports is: 80 8095 12995 20481 and the range 32768 - 61000 The client doesn't require any incoming ports.
Source:Forum Index - General Discussion - Which ports need to be open