@property<EOL><INDENT>def address(self):<DEDENT>
addresses = []<EOL>addresses = self.to_addresses + self.from_address<EOL>return addresses<EOL>
Property allowing one to get the relevant address(es).

        In earlier versions of this library, the model had an `address` field
        storing the e-mail address from which a message was received.  During
        later refactorings, it became clear that perhaps storing sent messages
        would also be useful, so the address field was replaced with two
        separate fields.