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