Dart

Read Delivery-Status Fields from a Bounce

Demonstrates the Chilkat Email.GetDeliveryStatusInfo method, which returns a named field from the message/delivery-status part of a delivery-status notification (DSN). It should be called only for an email identified as a delivery-status notification. This example loads a bounce message and reads its Action, Status, and Final-Recipient fields.

Background: When a message can't be delivered, the mail system returns a bounce as a multipart/report whose message/delivery-status part carries machine-readable fields: Action (e.g. failed), Status (a numeric code like 5.1.1 meaning "no such mailbox"), and Final-Recipient (the address that failed). Parsing these lets a program automatically detect hard bounces and prune bad addresses from a mailing list.

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Dart

import 'package:chilkat/chilkat.dart';

void main() {
  // Demonstrates the GetDeliveryStatusInfo method, which returns a field from the
  // message/delivery-status part of a delivery-status notification (DSN / bounce).
  // Call it only for an email that is a delivery-status notification.

  final email = CkEmail();

  try {
    email.loadEml('qa_data/eml/dsn_bounce.eml');
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // Read individual fields from the message/delivery-status part.
  print('Action: ${email.getDeliveryStatusInfo('Action')}');
  print('Status: ${email.getDeliveryStatusInfo('Status')}');
  print('Final-Recipient: ${email.getDeliveryStatusInfo('Final-Recipient')}');

  // Note: The path "qa_data/..." is a relative local filesystem path,
  // relative to the current working directory of the running application.
}