Timed-delivery SMTP - Node mailing amqp

Hi everyone! I started this project because I needed an smtp able to manage the timing of email delivery, with full control over the whole procedure.

I started from the nodemailer-amqp-example project, which is an example of how to handle a queue with the RabbitMQ broker and NodeJs.

I turned the publisher.js process into an SMTP server, and replaced the server.js process with an ad hoc Postfix. I also had to rewrite one of the dependencies because of some charset conversion issues, project here: mailparser-iconv-full .

So, what is it for?

It's for when you need to send a large amount of email, usually newsletters, and hand off to an external system the job of spreading the sending out over time.

What can you use it with?

With any SMTP client

Below are the link to the github project and the installation guide 🙂

The most important parameter is in config.json, delaysend, which defines how many milliseconds pass between one email and the next.

node-mailing-amqp

Installation and startup

Requirements

Install the rabbitmq broker

(on mac)

brew install rabbitmq

on ubuntu, go to the rabbimq website https://www.rabbitmq.com , download the deb and run:

dpkg -i rabbitmq.deb

the name will obviously vary.

Install postfix

apt-get install postfix

Install it as an internet site, and enter a valid FQDN

After that, go to the file

/etc/postfix/master.cf

and change the listening port

from the line

smtpd      inet  n       -       y       -       -       smtpd

to the line

9267      inet  n       -       y       -       -       smtpd

this way we'll have port 9267 listening on localhost

Installation

Clone the git project with git clone and move into the folder

cd node-mailing-amqp

Install the required dependencies

npm install --production

Create the log folders

./setup.sh

Make sure the RabbitMQ server is running, and also check that the configuration in config.json is correct.

Running

This project is made of three parts:

1. Postfix SMTP server . This is the actual service that will ultimately send the emails, it runs on localhost (port 9267) and only accepts mail from localhost.
2. Subscriber process (subscriber.js). This is the process that fetches messages from the rabbit queue and sends them out through postfix. Each fetch is timed by the config.delaysend value in the config.json file
3. Publisher process (publisher.js). This is the bridge smtp that validates the user sending the email, and puts the email to be delivered into the rabbit queue

You can start all the processes with the command (inside the folder)

./restart.sh

Setting up credentials

Edit the auth.json file and add the accounts that the system will use

Example:

{
	"users": [{
		"username": "test1",
		"password": "test1"
	}, {
		"username": "test2",
		"password": "test2"
	}, {
		"username": "test3",
		"password": "test3"
	}, {
		"username": "test4",
		"password": "test4"
	}, {
		"username": "test5",
		"password": "test5"
	}]
}

UTILITY

rabbitmqctl list_queues

delete the rabbit queue

python rabbitmqadmin purge queue name=node-mailing-amqp

The logs are inside the LOGS folder