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๐Ÿ“ฎ Email queue extending NodeMailer with multi SMTP transports and horizontally scaled applications support

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support support

MailTime

"Mail-Time" is NPM package for mail queue management. Build on top of the nodemailer package. Mail-Time made for single-server and horizontally scaled multi-server setups in mind.

Every MailTime instance can have type configured as Server or Client. Server type of MailTime is great for creating an emailing micro-service app.

The main difference between Server and Client type is that the Server handles the queue and sends email. While the Client only adds emails into the queue.

ToC

Main features:

  • ๐Ÿ‘จโ€๐Ÿ”ฌ ~94% tests coverage;
  • ๐Ÿ“ฆ Two simple dependencies, written from scratch for top performance;
  • ๐Ÿข Synchronize email queue across multiple (horizontally scaled) servers;
  • ๐Ÿ’ช Bulletproof design, built-in retries.

How does it work?

Redundant solution for email transmission.

Single point of failure

Issue - mitigate a single point of failure via persistent queue and re-send attempts

|----------------|         |------|         |------------------|
|  Other mailer  | ------> | SMTP | ------> |  ^_^ Happy user  |
|----------------|         |------|         |------------------|

The scheme above will work as long as SMTP service is available
or connection between your server and SMPT is up. Once network
failure occurs or SMTP service is down - users won't be happy

|----------------|  \ /    |------|         |------------------|
|  Other mailer  | --X---> | SMTP | ------> | 0_o Disappointed |
|----------------|  / \    |------|         |------------------|
                     ^- email lost in vain

Single SMTP solution may work in case of network or other failures
As long as MailTime has not received confirmation what email is sent
it will keep the letter in the queue and retry to send it again

|----------------|    /    |------|         |------------------|
|   Mail Time    | --X---> | SMTP | ------> |  ^_^ Happy user  |
|---^------------|  /      |------|         |------^-----------|
     \-------------/ ^- We will try later         /
      \- put it back into queue                  /
       \----------Once connection is back ------/

Multiple SMTP providers

Rotate email transports by using multiple SMTP providers. MailTime support two strategies backup (rotate when failed) and balancer (round-robin rotation)

                           |--------|
                     /--X--| SMTP 1 |
                    /   ^  |--------|
                   /    \--- Retry with next provider
|----------------|/        |--------|         |------------------|
|   Mail Time    | ---X--> | SMTP 2 |      /->|  ^_^ Happy user  |
|----------------|\   ^    |--------|     /   |------------------|
                   \  \--- Retry         /
                    \      |--------|   /
                     \---->| SMTP 3 |--/
                           |--------|

Sending emails from cluster of servers

It is common to have horizontally scaled "Cluster" of servers for load-balancing and for durability.

Most modern application has scheduled or recurring emails. For example, once a day โ€” with recent news and updates. It won't be an issue with a single server setup โ€” the server would send emails at a daily interval via timer or CRON. But in "Cluster" implementation โ€” each server will attempt to send the same email. MailTime built to avoid sending the same email multiple times to a user from horizontally scaled applications.

For the maximum durability and agility each Application Server can run MailTime in the "Server" mode:

|===================THE=CLUSTER===================| |=QUEUE=|
| |----------|     |----------|     |----------|  | |       |   |--------|
| |   App    |     |   App    |     |   App    |  | |       |-->| SMTP 1 |------\
| | Server 1 |     | Server 2 |     | Server 3 |  | |       |   |--------|       \
| |-----\----|     |----\-----|     |----\-----|  | |       |                |-------------|
|        \---------------\----------------\---------->      |   |--------|   |     ^_^     |
|                                                 | |       |-->| SMTP 2 |-->| Happy users |
| Each "App Server"                               | |       |   |--------|   |-------------|
| runs MailTime as a "Server"                     | |       |                    /
| for the maximum durability                      | |       |   |--------|      /
|                                                 | |       |-->| SMTP 3 |-----/
|                                                 | |       |   |--------|
|=================================================| |=======|

To split roles MailTime can run on a dedicated machine as micro-service. This case is great for private email servers with implemented authentication via rDNS and PTR records:

|===================THE=CLUSTER===================| |=QUEUE=| |===Mail=Time===|
| |----------|     |----------|     |----------|  | |       | |               |   |--------|
| |   App    |     |   App    |     |   App    |  | |       | | Micro-service |-->| SMTP 1 |------\
| | Server 1 |     | Server 2 |     | Server 3 |  | |       | | running       |   |--------|       \
| |-----\----|     |----\-----|     |----\-----|  | |       | | MailTime as   |                |-------------|
|        \---------------\----------------\---------->      | | "Server" only |   |--------|   |     ^_^     |
|                                                 | |       | | sending       |-->| SMTP 2 |-->| Happy users |
| Each "App Server" runs MailTime as              | |       | | emails        |   |--------|   |-------------|
| a "Client" only placing emails to the queue.    | |    <--------            |                    /
|                                                 | |    -------->            |   |--------|      /
|                                                 | |       | |               |-->| SMTP 3 |-----/
|                                                 | |       | |               |   |--------|
|=================================================| |=======| |===============|

Features

  • Email Queue - Managed via MongoDB, Redis, or Custom Queue. Storage-based queue will survive server reboots and failures
  • Made for horizontally scaled multi-server setups - MailTime is made to run in multi-server environments, like "Clusters", multiple app instances, load balanced solutions, and replications. MailTime is the perfect fit for applications scaled on a single machine, multiple virtual servers, multiple "bare metal" servers, within single or multiple data centers
  • Email concatenation - Reduce amount of sent emails to a single user with concatenation, and avoid mistakenly duplicated emails. When "email concatenation" is enabled the same emails (checked by addressee and content) won't be sent twice. If emails are sent multiple times, due to issues in logic or application failures, - enable "email concatenation" to solve this behavior
  • Multiple NodeMailer/SMTP transports โ€” Support for multiple SMPT transports implemented in two modes - backup and balancing. Use this feature to reduce the cost of SMTP services and add extra layer of durability. When one of the transports is failing to send an email โ€” mail-time will switch to the next one
  • Sending retries โ€” Built-in retries for failed to send emails due to network or other failures
  • Templating โ€” Built with support of Mustache-like placeholders, see templating docs

Installation

To implement Server functionality โ€” begin with installing nodemailer, although this package meant to be used with nodemailer, it's not added as the dependency, as nodemailer not needed by Client, and to give freedom to choose nodemailer's version to fit every project needs:

npm install --save nodemailer

Install MailTime package:

# for node@>=14.20.0
npm install --save mail-time

# for node@<14.20.0
npm install --save mail-time@=1.3.4

# for node@<8.9.0
npm install --save mail-time@=0.1.7

Basic usage

Setup Nodemailer's transports, Queue storage, and MailTime instance

Steps to get started

See steps 1-4 below to learn about different parts of MailTime library and how it can get used. From configuration options to sending email

  1. Require mail-time package
  2. Create NodeMailer's transports
  3. Initiate mail-time server
  4. Start sending emails

1. Require package

// import as ES Module
import { MailTime, MongoQueue, RedisQueue } from 'mail-time';

// require as CommonJS
const { MailTime, MongoQueue, RedisQueue } = require('mail-time');

2. Create NodeMailer's transports

For compatibility and flexibility MailTime has no dependency on nodemailer it should be installed and imported manually. Create one or more "SMTP transports" before initializing new MailTime instance.

For details and full list of options available in .createTransport() see nodemailer docs

// transports.js
import nodemailer from 'nodemailer';
// Use DIRECT transport
// and enable sending email from localhost
// install "nodemailer-direct-transport" NPM package:
import directTransport from 'nodemailer-direct-transport';

const transports = [];
const directTransportOpts = {
  pool: false,
  direct: true,
  name: 'mail.example.com',
  from: 'no-reply@example.com',
};
transports.push(nodemailer.createTransport(directTransport(directTransportOpts)));
// IMPORTANT: Add `.options` to a newly created transport,
// this is necessary to make sure options are available to MailTime package:
transports[0].options = directTransportOpts;

// Private SMTP
transports.push(nodemailer.createTransport({
  host: 'smtp.example.com',
  from: 'no-reply@example.com',
  auth: {
    user: 'no-reply',
    pass: 'xxx'
  },
}));

// Google Apps SMTP
transports.push(nodemailer.createTransport({
  host: 'smtp.gmail.com',
  from: 'no-reply@mail.example.com',
  auth: {
    user: 'no-reply@mail.example.com',
    pass: 'xxx'
  },
}));

// Mailing service (SparkPost as example)
transports.push(nodemailer.createTransport({
  host: 'smtp.sparkpostmail.com',
  port: 587,
  from: 'no-reply@mail2.example.com',
  auth: {
    user: 'SMTP_Injection',
    pass: 'xxx'
  },
}));

export { transports };

3. Initiate mail-time

Create new instance of MailTime in the Server mode, โ€” it will be able to send and add emails to the queue.

3a. Initiate and connect to Redis

Connecting to Redis before initiating new MailTime instance:

// mail-queue.js
import { MailTime, RedisQueue } from 'mail-time';
import { createClient } from 'redis';
import { transports } from './transports.js';

// Use REDIS_URL environment variable to store connection string to MongoDB
// example: "REDIS_URL=redis://127.0.0.1:6379/myapp node mail-micro-service.js"
const redisClient = await createClient({ url: process.env.REDIS_URL }).connect();
const mailQueue = new MailTime({
  transports,
  queue: new MongoQueue({
    client: redisClient,
  }),
  josk: {
    adapter: {
      type: 'redis',
      client: redisClient,
    }
  },
  template: MailTime.Template // Use default template
  from(transport) {
    // To pass spam-filters `from` field should be correctly set
    // for each transport, check `transport` object for more options
    return `"Awesome App" <${transport.options.from}>`;
  },
  onError(error, email, details) {
    console.log(`Email "${email.mailOptions.subject}" wasn't sent to ${email.mailOptions.to}`, error, details);
  },
  onSent(email, details) {
    console.log(`Email "${email.mailOptions.subject}" successfully sent to ${email.mailOptions.to}`, details);
  },
});

export { mailQueue };

3b. Initiate and connect to MongoDB

Connecting to MongoDB before initiating new MailTime instance:

// mail-queue.js
import { MailTime, MongoQueue } from 'mail-time';
import { MongoClient } from 'mongodb';
import { transports } from './transports.js';

// Use MONGO_URL environment variable to store connection string to MongoDB
// example: "MONGO_URL=mongodb://127.0.0.1:27017/myapp node mail-micro-service.js"
const mongodb = (await MongoClient.connect(process.env.MONGO_URL)).db('database');
const mailQueue = new MailTime({
  transports,
  queue: new MongoQueue({
    db: mongodb,
  }),
  josk: {
    adapter: {
      type: 'mongo',
      db: mongodb,
    }
  },
  template: MailTime.Template // Use default template
  from(transport) {
    // To pass spam-filters `from` field should be correctly set
    // for each transport, check `transport` object for more options
    return `"Awesome App" <${transport.options.from}>`;
  },
  onError(error, email, details) {
    console.log(`Email "${email.mailOptions.subject}" wasn't sent to ${email.mailOptions.to}`, error, details);
  },
  onSent(email, details) {
    console.log(`Email "${email.mailOptions.subject}" successfully sent to ${email.mailOptions.to}`, details);
  },
});

export { mailQueue };

3c. Optionally create Client type of MailTime

Only one MailTime Server instance required to send email. In the other parts of an app (like UI units or in sub-apps) use mail-time in the Client mode to add emails to queue

// mail-queue.js
import { MailTime, RedisQueue } from 'mail-time';
import { createClient } from 'redis';

const mailQueue = new MailTime({
  type: 'client',
  queue: new RedisQueue({
    client: await createClient({ url: 'redis://url' }).connect()
  }),
});

export { mailQueue };

4. Send email

Import created mailQueue where needed and call .sendMail() method. See NodeMailer's message configuration documentation for details

import { mailQueue } from './mail-queue.js';

await mailQueue.sendMail({
  to: 'user@gmail.com',
  subject: 'You\'ve got an email!',
  text: 'Plain text message',
  html: '<h1>HTML</h1><p>Styled message</p>'
});

Using MongoDB for queue and scheduler

MailTime uses separate storage for Queue management and Scheduler. In the example below MongoDB is used for both

import { MailTime, MongoQueue } from 'mail-time';
import { MongoClient } from 'mongodb';
import { transports } from './transports.js';

const db = (await MongoClient.connect('mongodb://url')).db('database');
const mailQueue = new MailTime({
  queue: new MongoQueue({
    db: db,
  }),
  josk: {
    adapter: {
      type: 'mongo',
      db: db,
    }
  },
  transports,
  from(transport) {
    // To pass spam-filters `from` field should be correctly set
    // for each transport, check `transport` object for more options
    return `"Awesome App" <${transport.options.from}>`;
  }
});

Using MongoDB for queue and Redis for scheduler

MailTime uses separate storage for Queue management and Scheduler. In the example below MongoDB is used for queue and Redis is used for scheduler

import { MailTime, MongoQueue } from 'mail-time';
import { MongoClient } from 'mongodb';
import { createClient } from 'redis';
import { transports } from './transports.js';

const mailQueue = new MailTime({
  queue: new MongoQueue({
    db: (await MongoClient.connect('mongodb://url')).db('database'),
  }),
  josk: {
    adapter: {
      type: 'redis',
      client: await createClient({ url: 'redis://url' }).connect(),
    }
  },
  transports,
  from(transport) {
    return `"Awesome App" <${transport.options.from}>`;
  }
});

Using Redis for queue and MongoDB for scheduler

MailTime uses separate storage for Queue management and Scheduler. In the example below Redis is used for queue and MongoDB is used for scheduler

import { MailTime, RedisQueue } from 'mail-time';
import { MongoClient } from 'mongodb';
import { createClient } from 'redis';
import { transports } from './transports.js';

const mailQueue = new MailTime({
  queue: new RedisQueue({
    client: await createClient({ url: 'redis://url' }).connect(),
  }),
  josk: {
    adapter: {
      type: 'mongo',
      db: (await MongoClient.connect('mongodb://url')).db('database'),
    }
  },
  transports,
  from(transport) {
    return `"Awesome App" <${transport.options.from}>`;
  }
});

Using Redis for queue and scheduler

MailTime uses separate storage for Queue management and Scheduler. In the example below Redis is used for both

import { MailTime, RedisQueue } from 'mail-time';
import { MongoClient } from 'mongodb';
import { createClient } from 'redis';
import { transports } from './transports.js';

const redisClient = await createClient({ url: 'redis://url' }).connect();
const mailQueue = new MailTime({
  queue: new RedisQueue({
    client: redisClient,
  }),
  josk: {
    adapter: {
      type: 'redis',
      client: redisClient,
    }
  },
  transports,
  from(transport) {
    return `"Awesome App" <${transport.options.from}>`;
  }
});

Two MailTime instances usage example

Create two MailTime instances with different settings. One for urgent (e.g. "transactional" emails), and another one for other types of emails (e.g. "marketing" emails)

import { MailTime, RedisQueue } from 'mail-time';
import { createClient } from 'redis';
import { transports } from './transports.js';
const redisClient = await createClient({ url: 'redis://url' }).connect();

// CREATE mailQueue FOR NON-URGENT EMAILS WHICH IS OKAY TO CONCATENATE
const mailQueue = new MailTime({
  queue: new RedisQueue({
    client: redisClient,
  }),
  transports,
  strategy: 'backup',
  failsToNext: 1,
  concatEmails: true,
  josk: {
    adapter: {
      type: 'redis',
      client: redisClient
    },
    zombieTime: 120000
  }
});

// CREATE mailInstantQueue FOR TRANSACTIONAL EMAILS AND ALERTS
const mailInstantQueue = new MailTime({
  queue: new RedisQueue({
    client: redisClient,
    prefix: 'instant'
  }),
  transports,
  prefix: 'instant',
  retryDelay: 2000,
  strategy: 'backup',
  failsToNext: 1,
  concatEmails: false,
  josk: {
    adapter: {
      type: 'redis',
      client: redisClient
    },
    zombieTime: 20000
  }
});

await mailQueue.sendMail({
  to: 'user@gmail.com',
  subject: 'You\'ve got an email!',
  text: 'Plain text message',
  html: '<h1>HTML</h1><p>Styled message</p>'
});

await mailInstantQueue.sendMail({
  to: 'user@gmail.com',
  subject: 'Sign in request',
  text: 'Your OTP login code: xxxx:',
  html: '<h1>Code:</h1><code>XXXX</code>'
});

Passing variables to the template

All options passed to the .sendMail() method are available inside text, html, and global templates

const templates = {
  global: '<html xmlns="http://www.w3.org/1999/xhtml"><head><title>{{subject}}</title></head><body>{{{html}}}<footer>Message sent to @{{username}} user ({{to}})</footer></body></html>',
  signInCode: {
    text: 'Hello @{{username}}! Here\'s your login code: {{code}}',
    html: `<h1>Sign-in request</h1><p>Hello @{{username}}! <p>Copy your login code below:</p> <pre><code>{{code}}</code></pre>`
  }
};

const mailQueue = new MailTime({
  queue: new RedisQueue({ /* ... */ }),
  template: templates.global
});

await mailQueue.sendMail({
  to: 'user@gmail.com',
  subject: 'Sign-in request',
  username: 'johndoe',
  code: 'XXXXX-YY',
  text: templates.signInCode.text,
  html: templates.signInCode.html
});

API

All available constructor options and .sendMail() method API overview

new MailTime(opts) constructor

  • opts {object} - Configuration object
  • opts.type {string} - [Optional] client or server, default - server
  • opts.queue {RedisQueue|MongoQueue|CustomQueue} - Queue storage driver instance
  • opts.transports {[object]} - [Required for "server"] An array of nodemailer's transports, returned from nodemailer.createTransport({}). Required for {type: 'server'}
  • opts.josk {object} - [Required for "server"] JoSk package options
  • opts.josk.adapter {object|RedisAdapter|MongoAdapter|CustomAdapter} - Config object or Adapter instance
  • opts.josk.adapter.type {string} - One of mongo or redis; Pass josk.adapter.type to avoid burden of creating Adapter instance manually
  • opts.josk.adapter.client {RedisClient} - RedisClient instance
  • opts.josk.adapter.db {Db} - Mongo's Db instance
  • opts.josk[option] {mix} - Any other options passed to JoSk instance
  • opts.from {function} - [Optional] A function which returns string of from field, format: "MyApp" <user@example.com>
  • opts.strategy {string} - [Optional] backup or balancer, default - backup. If set to backup, first transport will be used unless failed to send failsToNext times. If set to balancer - transports will be used equally in round robin chain
  • opts.failsToNext {number} - [Optional] After how many failed "send attempts" switch to the next transport, applied only for backup strategy, default - 4
  • opts.prefix {string} - [Optional] Use unique prefixes to create multiple MailTime instances within the same application
  • opts.retries {number} - [Optional] How many times resend failed emails, default - 60
  • opts.retryDelay {number} - [Optional] Interval in milliseconds between send re-tries, default - 60000
  • opts.keepHistory {boolean} - [Optional] By default sent emails not stored in the database. Set { keepHistory: true } to keep queue task as it is in the database, default - false
  • opts.concatEmails {boolean} - [Optional] Concatenate email by to field (e.g. to the same addressee), default - false
  • opts.concatSubject {string} - [Optional] Email subject used in concatenated email, default - Multiple notifications
  • opts.concatDelimiter {string} - [Optional] HTML or plain string delimiter used between concatenated email, default - <hr>
  • opts.concatDelay {number} - [Optional] Time in milliseconds while emails are waiting to be concatenated, default - 60000
  • opts.revolvingInterval {number} - [Optional] Interval in milliseconds in between queue checks, default - 256
  • opts.template {string} - [Optional] Mustache-like template, default - {{{html}}}, all options passed to sendMail is available in Template, like to, subject, text, html or any other custom option. Use {{opt}} for string placeholders and {{{opt}}} for html placeholders
  • opts.onError(error, email, details) {function} - [Optional] called when email has failed to get sent and exhausted all send attempts (opts.retries), called with 3 arguments:
    • error {Error|object} - Error object
    • email {object} - email's object
    • details {object} - not always present, details from SMTP protocol
  • opts.onSent(email, details) {function} - [Optional] called when email was successfully handed over to receiving/recipient's SMTP server, called with 2 arguments:
    • email {object} - email's object
    • details {object} - not always present, details from SMTP server/protocol
import { MailTime, MongoQueue, RedisQueue } from 'mail-time';
import nodemailer from 'nodemailer';
import { createClient } from 'redis';

const redisClient = await createClient({ url: 'redis://url' }).connect();

const mailQueue = new MailTime({
  type: 'server',
  strategy: 'backup',
  prefix: 'appMailQueue',
  transports: [nodemailer.createTransport({/* ... */})],
  failsToNext: 4,
  retries: 60,
  retryDelay: 60000,
  keepHistory: false,
  concatEmails: false,
  concatDelay: 60000,
  concatDelimiter: '<hr>',
  concatSubject: 'Multiple notifications',
  revolvingInterval: 256,
  template: '{{{html}}}',
  queue: new RedisQueue({
    client: redisClient,
    prefix: 'appMailQueue',
  }),
  josk: {
    adapter: {
      type: 'redis',
      client: redisClient,
    }
  },
  from(transport) {
    // To pass spam-filters `from` field should be correctly set
    // for each transport, check `transport` object for more options
    return `"App Name" <${transport.options.from}>`;
  },
  onError(error, email, details) {
    console.log(`Email "${email.mailOptions.subject}" wasn't sent to ${email.mailOptions.to}`, error, details);
  },
  onSent(email, details) {
    console.log(`Email "${email.mailOptions.subject}" successfully sent to ${email.mailOptions.to}`, details);
  },
});

await mailQueue.sendMail({
  to: 'johndoe@example.com',
  subject: 'Email subject',
  text: 'You have got email!',
  html: '<p>You have got email!</p>',
});

new RedisQueue(opts) constructor

Create Redis Queue instance. Use for opts.queue when creating MailTime instance

  • opts {object} - Configuration object
  • opts.client {RedisClient} - Required, Redis'es RedisClient instance, like one returned from await redis.createClient().connect() method
  • opts.prefix {string} - Optional prefix for scope isolation; use when creating multiple MailTime instances within the single application
import { MailTime, RedisQueue } from 'mail-time';
import { createClient } from 'redis';

new RedisQueue({
  client: await createClient({ url: 'redis://url' }).connect(),
  prefix: 'appMailQueue',
});

new MongoQueue(opts) constructor

Create MongoDB Queue instance. Use for opts.queue when creating MailTime instance

  • opts {object} - Configuration object
  • opts.db {Db} - Required, Mongo's Db instance, like one returned from MongoClient#db()
  • opts.prefix {string} - Optional prefix for scope isolation; use when creating multiple MailTime instances within the single application
import { MailTime, MongoQueue } from 'mail-time';
import { MongoClient } from 'mongodb';

new MongoQueue({
  db: (await MongoClient.connect('mongodb://url')).db('database'),
  prefix: 'appMailQueue',
});

sendMail(opts)

Add email to the queue. Returns Promise<string> unique email's uuid

  • opts {object} - Configuration object
  • opts.sendAt {number} - When email should be sent, default - Date.now()
  • opts.template {string} - Email specific template, this will override default template passed to MailTime constructor
  • opts.concatSubject {string} - Email specific concatenation subject, this will override default concatenation subject passed to MailTime constructor
  • opts[key] {mix} - Other custom and NodeMailer specific options, like text, html and to, learn more here. Note: if attachments are used via path โ€” file must exists on all micro-services servers

cancelMail(uuid)

Remove email from queue. Returns Promise<boolean> โ€” true if cancelled or false if not found, was sent, or was cancelled previously. Throws Error

  • uuid {string|promise} โ€” email's uuid returned from .sendEmail() method
import { mailQueue } from './mail-queue.js';

const uuid = await mailQueue.sendMail({
  to: 'johndoe@example.com',
  subject: 'Email subject',
  text: 'You have got email!',
  html: '<p>You have got email!</p>',
});

await mailQueue.cancelMail(uuid);

ping()

Ping MailTime instance, its scheduler, and its queue. Returns Promise<object>

const mailQueue = new MailTime({ /* ... */ });

const pingResult = await mailQueue.ping();
console.log(pingResult)
/**
In case of the successful response
{
  status: 'OK',
  code: 200,
  statusCode: 200,
}

Failed response
{
  status: 'Error reason',
  code: 500,
  statusCode: 500,
  error: ErrorObject
}
*/

static MailTime.Template

Simple and bulletproof HTML template, see its source. Usage example:

import { MailTime, MongoQueue, RedisQueue } from 'mail-time';

// Make it default
const mailQueue = new MailTime({
  /* .. */
  template: MailTime.Template
});

// For single letter
mailQueue.sendMail({
  /* .. */
  template: MailTime.Template
});

Template Example

Pass custom template via template property to .sendMail() method

mailQueue.sendMail({
  to: 'user@gmail.com',
  userName: 'Mike',
  subject: 'Sign up confirmation',
  text: 'Hello {{userName}}, \r\n Thank you for registration \r\n Your login: {{to}}',
  html: '<div style="text-align: center"><h1>Hello {{userName}}</h1><p><ul><li>Thank you for registration</li><li>Your login: {{to}}</li></ul></p></div>',
  template: '<body>{{{html}}}</body>'
});

Testing

  1. Clone this package
  2. Start local or obtain URLs for remote MongoDB and Redis servers
  3. In Terminal (Console) go to directory where package was cloned
  4. Then run:
# Before running tests make sure NODE_ENV === development
# Install NPM dependencies
npm install --save-dev

# DEFAULT RUN
REDIS_URL="redis://127.0.0.1:6379" MONGO_URL="mongodb://127.0.0.1:27017/npm-mail-time-test-001" npm test

# OPTIONALLY RUN WITH CUSTOM DOMAIN
EMAIL_DOMAIN="your-domain.com" REDIS_URL="redis://127.0.0.1:6379" MONGO_URL="mongodb://127.0.0.1:27017/npm-mail-time-test-001" npm test

# IF SOME TESTS ARE FAILING: ENABLE DEBUG
DEBUG="true" REDIS_URL="redis://127.0.0.1:6379" MONGO_URL="mongodb://127.0.0.1:27017/npm-mail-time-test-001" npm test

# Be patient, tests are taking around 8 mins

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