'Adds the recipient of the email to the opt-out list and returns
that address.'

def opt_out(self, msg_hash):

    email = self.get_recipient(msg_hash)
    if email:
        o = self.opt_table
        try:
            o.insert().values({o.c.email: email, o.c.msg_hash: msg_hash}).execute()
            g.stats.simple_event('share.opt_out')
            has_opted_out(email, _update=True)
            opt_count(_update=True)
            return (email, True)
        except sa.exc.DBAPIError:
            return (email, False)
    return (None, False)
