meteor/packages/email/email.js

var Future = Npm.require('fibers/future');
var urlModule = Npm.require('url');
var nodemailer = Npm.require('node4mailer');

Email = {};
EmailTest = {};

EmailInternals = {
  NpmModules: {
    mailcomposer: {
      version: Npm.require('node4mailer/package.json').version,
      module: Npm.require('node4mailer/lib/mail-composer')
    },
    nodemailer: {
      version: Npm.require('node4mailer/package.json').version,
      module: Npm.require('node4mailer')
    }
  }
};

var MailComposer = EmailInternals.NpmModules.mailcomposer.module;

var makeTransport = function (mailUrlString) {
  var mailUrl = urlModule.parse(mailUrlString, true);

  if (mailUrl.protocol !== 'smtp:' && mailUrl.protocol !== 'smtps:') {
    throw new Error("Email protocol in $MAIL_URL (" +
                    mailUrlString + ") must be 'smtp' or 'smtps'");
  }

  if (mailUrl.protocol === 'smtp:' && mailUrl.port === '465') {
    Meteor._debug("The $MAIL_URL is 'smtp://...:465'.  " +
                  "You probably want 'smtps://' (The 's' enables TLS/SSL) " +
                  "since '465' is typically a secure port.");
  }

  // Allow overriding pool setting, but default to true.
  if (!mailUrl.query) {
    mailUrl.query = {};
  }

  if (!mailUrl.query.pool) {
    mailUrl.query.pool = 'true';
  }

  var transport = nodemailer.createTransport(
    urlModule.format(mailUrl));

  transport._syncSendMail = Meteor.wrapAsync(transport.sendMail, transport);
  return transport;
};

var getTransport = function() {
  // We delay this check until the first call to Email.send, in case someone
  // set process.env.MAIL_URL in startup code. Then we store in a cache until
  // process.env.MAIL_URL changes.
  var url = process.env.MAIL_URL;
  if (this.cacheKey === undefined || this.cacheKey !== url) {
    this.cacheKey = url;
    this.cache = url ? makeTransport(url) : null;
  }
  return this.cache;
}

var nextDevModeMailId = 0;
var output_stream = process.stdout;

// Testing hooks
EmailTest.overrideOutputStream = function (stream) {
  nextDevModeMailId = 0;
  output_stream = stream;
};

EmailTest.restoreOutputStream = function () {
  output_stream = process.stdout;
};

var devModeSend = function (mail) {
  var devModeMailId = nextDevModeMailId++;

  var stream = output_stream;

  // This approach does not prevent other writers to stdout from interleaving.
  stream.write("====== BEGIN MAIL #" + devModeMailId + " ======\n");
  stream.write("(Mail not sent; to enable sending, set the MAIL_URL " +
               "environment variable.)\n");
  var readStream = new MailComposer(mail).compile().createReadStream();
  readStream.pipe(stream, {end: false});
  var future = new Future;
  readStream.on('end', function () {
    stream.write("====== END MAIL #" + devModeMailId + " ======\n");
    future.return();
  });
  future.wait();
};

var smtpSend = function (transport, mail) {
  transport._syncSendMail(mail);
};

/**
 * Mock out email sending (eg, during a test.) This is private for now.
 *
 * f receives the arguments to Email.send and should return true to go
 * ahead and send the email (or at least, try subsequent hooks), or
 * false to skip sending.
 */
var sendHooks = [];
EmailTest.hookSend = function (f) {
  sendHooks.push(f);
};

/**
 * @summary Send an email. Throws an `Error` on failure to contact mail server
 * or if mail server returns an error. All fields should match
 * [RFC5322](http://tools.ietf.org/html/rfc5322) specification.
 *
 * If the `MAIL_URL` environment variable is set, actually sends the email.
 * Otherwise, prints the contents of the email to standard out.
 *
 * Note that this package is based on **mailcomposer 4**, so make sure to refer to
 * [the documentation](https://github.com/nodemailer/mailcomposer/blob/v4.0.1/README.md)
 * for that version when using the `attachments` or `mailComposer` options.
 *
 * @locus Server
 * @param {Object} options
 * @param {String} [options.from] "From:" address (required)
 * @param {String|String[]} options.to,cc,bcc,replyTo
 *   "To:", "Cc:", "Bcc:", and "Reply-To:" addresses
 * @param {String} [options.inReplyTo] Message-ID this message is replying to
 * @param {String|String[]} [options.references] Array (or space-separated string) of Message-IDs to refer to
 * @param {String} [options.messageId] Message-ID for this message; otherwise, will be set to a random value
 * @param {String} [options.subject]  "Subject:" line
 * @param {String} [options.text|html] Mail body (in plain text and/or HTML)
 * @param {String} [options.watchHtml] Mail body in HTML specific for Apple Watch
 * @param {String} [options.icalEvent] iCalendar event attachment
 * @param {Object} [options.headers] Dictionary of custom headers - e.g. `{ "header name": "header value" }`. To set an object under a header name, use `JSON.stringify` - e.g. `{ "header name": JSON.stringify({ tracking: { level: 'full' } }) }`.
 * @param {Object[]} [options.attachments] Array of attachment objects, as
 * described in the [mailcomposer documentation](https://github.com/nodemailer/mailcomposer/blob/v4.0.1/README.md#attachments).
 * @param {MailComposer} [options.mailComposer] A [MailComposer](https://nodemailer.com/extras/mailcomposer/#e-mail-message-fields)
 * object representing the message to be sent.  Overrides all other options.
 * You can create a `MailComposer` object via
 * `new EmailInternals.NpmModules.mailcomposer.module`.
 */
Email.send = function (options) {
  for (var i = 0; i < sendHooks.length; i++)
    if (! sendHooks[i](options))
      return;

  if (options.mailComposer) {
    options = options.mailComposer.mail;
  }

  var transport = getTransport();
  if (transport) {
    smtpSend(transport, options);
  } else {
    devModeSend(options);
  }
};