def action_send_mail(self):
    active_record = self.env[self.res_model].browse(self.res_id)
    template = self.env.ref('portal.portal_share_template', False)
    note = self.env.ref('mail.mt_note')
    signup_enabled = self.env['ir.config_parameter'].sudo().get_param('auth_signup.invitation_scope') == 'b2c'

    if hasattr(active_record, 'access_token') and active_record.access_token or not signup_enabled:
        partner_ids = self.partner_ids
    else:
        partner_ids = self.partner_ids.filtered(lambda x: x.user_ids)
    # if partner already user or record has access token send common link in batch to all user
    for partner in self.partner_ids:
        share_link = active_record.get_base_url() + active_record._get_share_url(redirect=True, pid=partner.id)
        active_record.with_context(mail_post_autofollow=True).message_post_with_view(template,
            values={'partner': partner, 'note': self.note, 'record': active_record,
                    'share_link': share_link},
            subject=_("You are invited to access %s" % active_record.display_name),
            subtype_id=note.id,
            email_layout_xmlid='mail.mail_notification_light',
            partner_ids=[(6, 0, partner.ids)])
    # when partner not user send individual mail with signup token
    for partner in self.partner_ids - partner_ids:
        #  prepare partner for signup and send singup url with redirect url
        partner.signup_get_auth_param()
        share_link = partner._get_signup_url_for_action(action='/mail/view', res_id=self.res_id, model=self.model)[partner.id]
        active_record.with_context(mail_post_autofollow=True).message_post_with_view(template,
            values={'partner': partner, 'note': self.note, 'record': active_record,
                    'share_link': share_link},
            subject=_("You are invited to access %s" % active_record.display_name),
            subtype_id=note.id,
            email_layout_xmlid='mail.mail_notification_light',
            partner_ids=[(6, 0, partner.ids)])
    return {'type': 'ir.actions.act_window_close'}