'Create an instance of a POP3 server protocol.
@type addr: L{IAddress <twisted.internet.interfaces.IAddress>} provider
@param addr: The address of the POP3 client.
@rtype: L{POP3}
@return: A POP3 protocol.'

def buildProtocol(self, addr):

    p = protocol.ServerFactory.buildProtocol(self, addr)
    p.service = self.service
    return p
