OutlookAddIn_GraphController_saveMailMetadata.ts

export default class GraphController {
  private client: MSGraphClient;
  private metadataExtensionName = 'mmsharepoint.onmicrosoft.MailStorage';

  public saveMailMetadata(mailId: string, displayName: string, url: string, savedDate: Date) {
    const apiUrl = `/me/messages/${mailId}/extensions`;
    const metadataBody = {
      "@odata.type" : "microsoft.graph.openTypeExtension",
      "extensionName" : this.metadataExtensionName,
      "saveDisplayName" : displayName,
      "saveUrl" : url,
      "savedDate" : savedDate.toISOString()
    };
    this.client
      .api(apiUrl)
      .version('v1.0')
      .post(JSON.stringify(metadataBody))
      .then((response) => {
        console.log(response);
      });
  }
}