Dart

GMail SMTP Send using Previously Obtained OAuth2 Access Token

See more GMail SMTP/IMAP/POP Examples

Demonstrates how to send email using GMail and OAuth2 authentication. This example assumes an OAuth2 access token was previously obtained. Dart

import 'package:chilkat/chilkat.dart';

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

  // See Get GMail SMTP Access Token 
  // for sample code showing how to obtain a GMail SMTP access token for desktop apps.

  // In this example, our access token was previously saved to the following file which contains JSON like this:
  // 	{
  // 	 "access_token": "ya39.Ci-XA_C5bGgRDC3UaD-h0_NeL-DVIQnI2gHtBBBHkZzrwlARkwX6R3O0PCDEzRlfaQ",
  // 	 "token_type": "Bearer",
  // 	 "expires_in": 3600,
  // 	 "refresh_token": "1/r_2c_7jddspcdfesrrfKqfXtqo08D6Q-gUU0DsdfVMsx0c"
  // 	}
  // 
  final json = CkJsonObject();
  try {
    json.loadFile('qa_data/tokens/_gmailSmtp.json');
  } on ChilkatException {
    print('Failed to load GMail access token file.');
    return;
  }

  final accessToken = json.stringOf('access_token');

  final mailman = CkMailMan();

  // Set the properties for the GMail SMTP server:
  mailman.smtpHost = 'smtp.gmail.com';
  mailman.smtpPort = 587;
  mailman.startTLS = true;

  // The SMTP username should be the GMail address of the user's account that authorized your app to send email.
  mailman.smtpUsername = 'chilkat.support@gmail.com';
  mailman.oAuth2AccessToken = accessToken;

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

  email.subject = 'This is a test';
  email.body = 'This is a test';
  email.from = 'Chilkat <chilkat.support@gmail.com>';
  email.addTo('Chilkat Admin', 'admin@chilkatsoft.com');
  // To add more recipients, call AddTo, AddCC, or AddBcc once per recipient.

  // Call SendEmail to connect to the SMTP server and send.
  // The connection (i.e. session) to the SMTP server remains
  // open so that subsequent SendEmail calls may use the
  // same connection.  
  try {
    mailman.sendEmail(email);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // You may close the connection here.  If the connection is kept open, 
  // the next call to mailman.SendEmail will continue using the already-established connection
  // (and automatically re-connect if needed).
  try {
    mailman.closeSmtpConnection();
  } on ChilkatException {
    print('Connection to SMTP server not closed cleanly.');
  }

  print('Email Sent via GMail with OAuth2 authentication.');
}