Controls whether cached emails are included in the initial response when lookup status = progress. When set to false, all email fields will be null until the lookup is complete and all emails are fully verified. Use /checkStatus or Webhooks to retrieve the completed response with fully verified emails (status = complete). Defaults to true.
NOTE: Default will change to false on May 1st, 2026. No cached emails will be returned in the initial response. Use /checkStatus or webhooks to retrieve fully verified emails.