old_contents: ##############################################################################
  #
  #    Copyright (C) 2020 Compassion CH (http://www.compassion.ch)
  #    Releasing children from poverty in Jesus' name
  #    @author: Emanuel Cino <ecino@compassion.ch>
  #
  #    The licence is in the file __manifest__.py
  #
  ##############################################################################
  from odoo import api, models, fields, _
  from odoo.exceptions import UserError
  
  
  class ExportMailchimpWizard(models.TransientModel):
      _inherit = "partner.export.mailchimp"
  
      @api.multi
      def get_mailing_contact_id(self, partner_id, force_create=False):
          # Avoid exporting opt_out partner
          if force_create:
              partner = self.env["res.partner"].browse(partner_id)
              if partner.opt_out:
                  return False
          # Push the partner_id in mailing_contact creation
          return super(
              ExportMailchimpWizard, self.with_context(default_partner_id=partner_id)
          ).get_mailing_contact_id(partner_id, force_create)
  
new_contents: ##############################################################################
  #
  #    Copyright (C) 2020 Compassion CH (http://www.compassion.ch)
  #    Releasing children from poverty in Jesus' name
  #    @author: Emanuel Cino <ecino@compassion.ch>
  #
  #    The licence is in the file __manifest__.py
  #
  ##############################################################################
  from odoo import api, models, fields, _
  from odoo.exceptions import UserError
  
  
  class ExportMailchimpWizard(models.TransientModel):
      _inherit = "partner.export.mailchimp"
  
      @api.multi
      def get_mailing_contact_id(self, partner_id, force_create=False):
          # Avoid exporting opt_out partner
          if force_create and partner_id.opt_out:
              return False
          # Push the partner_id in mailing_contact creation
          return super(
              ExportMailchimpWizard, self.with_context(default_partner_id=partner_id)
          ).get_mailing_contact_id(partner_id, force_create)
  
subject: FIX opt_out prevention for mailchimp export