code: function sendMail (template, locals, options, callback) {
    var self = this
    this.render(template, locals, function (err, html, text) {
      if (err) { return callback(err) }
  
      self.transport.sendMail({
        from: options.from || defaultFrom,
        to: options.to,
        subject: options.subject,
        html: html,
        text: text
      }, callback)
    })
  }
docs: Helper function to send e-mails using templates