Sending an SMTP email in Dart

Question

I looked through the API documentation and language guide, but I did not see anything about sending emails in Dart. I also checked this google groups post, but it's quite old by Dart standards.

Is this possible to do? I know that I can always use the Process class to invoke external programs, but I'd prefer a real Dart solution if there's any.

Answer 1

There's a library called mailer, which does exactly what you asked for: sends out emails.

Set it as a dependency in your pubspec.yaml and run pub install:

dependencies:
  mailer: any

I will give a simple example using Gmail on my local Windows machine:

import 'package:mailer/mailer.dart';

main() {
  var options = new GmailSmtpOptions()
    ..username = '[email protected]'
    ..password = 'my gmail password'; // If you use Google app-specific passwords, use one of those.

  // As pointed by Justin in the comments, be careful what you store in the source code.
  // Be extra careful what you check into a public repository.
  // I'm merely giving the simplest example here.

  // Right now only SMTP transport method is supported.
  var transport = new SmtpTransport(options);

  // Create the envelope to send.
  var envelope = new Envelope()
    ..from = '[email protected]'
    ..fromName = 'Your company'
    ..recipients = ['[email protected]', '[email protected]']
    ..subject = 'Your subject'
    ..text = 'Here goes your body message';

  // Finally, send it!
  transport.send(envelope)
    .then((_) => print('email sent!'))
    .catchError((e) => print('Error: $e'));
}

The GmailSmtpOptions is just a helper class. If you want to use a local SMTP server:

var options = new SmtpOptions()
  ..hostName = 'localhost'
  ..port = 25;

You can check here for all possible fields in the SmtpOptions class.

Here's an example using the popular Rackspace Mailgun:

var options = new SmtpOptions()
  ..hostName = 'smtp.mailgun.org'
  ..port = 465
  ..username = '[email protected]'
  ..password = 'from mailgun';

The library supports HTML emails and attachments as well. Check out the example to learn how to do that.

I am personally using mailer with Mailgun in production use.

Answer 2

== Updated Answer:
You can use official mailer library from pub.dev:
Add mailer library below your dependencies: at pubspec.yaml

dependencies:
mailer: ^3.2.1

Then make sure to import those two lines:

import 'package:mailer/mailer.dart';
import 'package:mailer/smtp_server.dart';

And you can create this method and use it wherever you want: (This is a example to send SMTP mail for Gmail)

void sendMail() async {

String username = '[email protected]';
String password = 'password';

  final smtpServer = gmail(username, password);
  final equivalentMessage = Message()
  ..from = Address(username, 'Your name')
  ..recipients.add(Address('[email protected]'))
  ..ccRecipients.addAll([Address('[email protected]'), '[email protected]'])
  ..bccRecipients.add('[email protected]')
  ..subject = 'Test Dart Mailer library :: ? :: ${DateTime.now()}'
  ..text = 'This is the plain text.\nThis is line 2 of the text part.'
  ..html = "<h1>Test</h1>\n<p>Hey! Here's some HTML content</p>";

  await send(equivalentMessage, smtpServer);
  }
}

But make sure that you enable (Less secure app access) at your Gmail Account Settings > Security to successfully integrate with your Email and send this mail.

• Documentation & full example: https://pub.dev/packages/mailer