Pug

npm install pug

Mail.configure({
  // ...
  templates: {
    engine: 'pug',
    viewsPath: './views/emails',
    extension: '.pug',
    cache: true,
  },
});

await Mail.to('user@example.com')
  .subject('Notification')
  .template('notification')
  .data({
    title: 'Account Update',
    message: 'New features available!',
    username: 'john',
    urgent: true,
    items: ['Feature A', 'Feature B'],
    timestamp: new Date().toISOString(),
  })
  .send();

doctype html
html
  head
    title= title
  body
    h1= message
    p Dear #{username},
    p This is a notification about your account activity.
    if urgent
      p.alert This requires immediate attention!
    ul
      each item in items
        li= item
    p Sent at: #{timestamp}

class WelcomeEmail extends Mailable {
  constructor(private user: { name: string; email: string }) {
    super();
  }

  build() {
    return this
      .subject(`Welcome, ${this.user.name}!`)
      .view('welcome', {
        name: this.user.name,
        email: this.user.email,
        appName: 'My App',
      });
  }
}