'Redirect the posting of message on res.users to the related employees.
This is done because when giving the context of Chatter on the
various mailboxes, we do not have access to the current partner_id.'

@api.multi
@api.returns('self', (lambda value: value.id))
def message_post(self, **kwargs):

    self.ensure_one()
    if (kwargs.get('message_type') == 'email'):
        return super(User, self).message_post(**kwargs)
    message_id = None
    employees = self._get_related_employees()
    if (not employees):
        return super(User, self).message_post(**kwargs)
    for employee in employees:
        message_id = employee.message_post(**kwargs)
    return message_id
