Dart

Send Encrypted Email to Multiple Recipients

Demonstrates how to create and send an S/MIME encrypted email to multiple recipients. The digital certificate of each recipient is required. The encrypting/sending process uses each recipient's digital certificate (which internally contains the public key). Each recipient decrypts the received email using his/her private key. Dart

import 'package:chilkat/chilkat.dart';

void main() {
  var success = false;

  // This example requires the Chilkat API to have been previously unlocked.
  // See Global Unlock Sample for sample code.

  // The mailman object is used for sending and receiving email.
  final mailman = CkMailMan();

  // Set the SMTP server.
  mailman.smtpHost = 'smtp.mymailserver.com';

  // Load each recipient's certificate into a Chilkat certificate object.
  // This example loads the certificates from files.  However, the Chilkat
  // certificate object provides other means for loading certificates,
  // such as from in-memory PEM strings, or in-memory binary DER encoded form, etc.
  final cert1 = CkCert();
  success = true;
  try {
    cert1.loadFromFile('recipient1.cer');
  } on ChilkatException {
    success = false;
  }
  if (!success) {
    print(cert1.lastErrorText);
    return;
  }

  final cert2 = CkCert();
  success = true;
  try {
    cert2.loadFromFile('recipient2.cer');
  } on ChilkatException {
    success = false;
  }
  if (!success) {
    print(cert2.lastErrorText);
    return;
  }

  final cert3 = CkCert();
  success = true;
  try {
    cert3.loadFromFile('recipient3.cer');
  } on ChilkatException {
    success = false;
  }
  if (!success) {
    print(cert3.lastErrorText);
    return;
  }

  // Create a new email object
  final email = CkEmail();

  email.subject = 'This email is encrypted and sent to 3 recipients';
  email.body = 'This is an S/MIME encrypted mail sent to 3 recipients';
  email.from = 'Chilkat Support <support@chilkatsoft.com>';

  // Make each of the certificates available for encrypting the email
  // by calling AddEncryptCert for each.
  success = true;
  try {
    email.addEncryptCert(cert1);
  } on ChilkatException {
    success = false;
  }
  if (success) {
    success = true;
    try {
      email.addEncryptCert(cert2);
    } on ChilkatException {
      success = false;
    }
  }

  if (success) {
    success = true;
    try {
      email.addEncryptCert(cert3);
    } on ChilkatException {
      success = false;
    }
  }

  if (!success) {
    print(email.lastErrorText);
    return;
  }

  // Add 3 recipients to the email (2 TO addresses, and 1 CC address)
  email.addTo('Recipient 1', 'admin@cknotes.com');
  email.addTo('Recipient 2', 'somebody001122@yahoo.com');
  success = true;
  try {
    email.addCC('Recipient 3', 'somebody123xyz@gmail.com');
  } on ChilkatException {
    success = false;
  }

  // Indicate that the email is to be sent encrypted.
  email.sendEncrypted = true;

  // Send the encrypted email...
  success = true;
  try {
    mailman.sendEmail(email);
  } on ChilkatException {
    success = false;
  }
  if (!success) {
    print(mailman.lastErrorText);
  } else {
    print('Encrypted Email Sent!');
  }
}