how to manage MAILING LISTS

How to manage mailing lists with foresight in 2021 ?

  1. First of all: why use a mailing list manager?

    CRM systems (such as Salesforce and Microsoft CRM)
    and business emails (such as Office 365 and Google Apps Gmail)
    they are not suitable for mass mailings.

    They were created for one-to-one communication.
    Often to avoid abuses they impose daily sending limits.

    Many times companies have to send emails to most of their contacts or to some selected groups.
    Bulk mailings must be managed with dedicated systems,
    capable of processing large amounts of messages and automatic unsubscriptions.

  2. Second step: where to look for these solutions?

    The easy answer is to look at “Saas” - Software as a service - offers
    (Mailchimp is the most famous system, Inxmail is less known, is used by large companies).

    Local installation versus cloud services is always an important choice.
    Our reflection is that the local option helps to “regain email control”, which we are promoting.

    Even if you decide to use a self-hosted application in the cloud,
    this allows you to easily change supplier while maintaining the same solution.

  3. Three osolutions are worth mentioning:

    • Sendy is mature but “closed source” and paid.

    • Listmonk is open source. Version 1 was released in 2021. It has been developed in Go,
      it comes as a standalone binary and the only dependency is a Postgres database. On GitHub it has 5.4k stars

    • Mailtrain is open source too. The first version was first released in 2016, version 2 in 2021.
      It uses a MySQL database. On GitHub it has 4.8k stars

In search of a clean interface, a list-centered solution, easy to maintain
and easy to restore in case of problems, we have considered listmonk as the best choice.

listmonk is a self-hosted, high performance mailing list and newsletter manager. 
It comes as a standalone binary and the only dependency is a Postgres database.

listmonk dashboard

First steps of the application

This is the original announcement on Hacker News:

knadh on July 12, 2019 [–]

Author here. To give some context on why listmonk was built, at work (regulated financial business), 
we have to deliver e-mails, mostly important updates, to 1.5mn+ customers regularly. 
We used phpList for the longest time and then tried MailTrain and Sendy before finally deciding to reinvent the wheel 
after running into a number of issues, of which, a few important ones are mentioned below.

- Performance. Unreasonably long amounts of time to send out e-mails. 
  phpList degraded to the point of taking several days to process a campaign. 
  listmonk can spawn N goroutines (~threads) and push e-mails to multiple SMTP servers. 
  On a commodity ec2 instance, we're able to send 1.5mn+ e-mails in a couple hours.

- Subscriber imports were extremely slow. Direct integration to keep subscribers in sync with external CRMs was cumbersome. 
  Direct DB inserts were complicated due to the complex table structures. listmonk imports 10k records/sec into a Postgres DB on a commodity ec2 instance.

- Segmentation. Often, we have to rapidly segment users by custom attributes and conditions and relay an update to them. 
  listmonk supports SQL expressions to segment users on their attributes that are defined as arbitrary JSON maps (thanks to Postgres JSONB type).

- Unavailability of dynamic templates. listmonk templates support Go template expressions so it's possible to write logic in messages to make them dynamic.

Kailash Nadhis a very active developer in the FOSS (Free and Open Source Software) area.
He works at Zerodha, India’s largest stock broker.
The blog of Zerodha’s technical staff is published at

The details

Listmonk is well documented for standard use (via web interface) and developers (via api).

listmonk Documentation

The solution is suitable for large lists (up to millions of subscribers) and also for small groups.
Thanks to the Querying and segmenting subscribers feature,
it lets you query and export a selection of subscribers based on their profiles and attributes.
The extracted data can be easily imported in a new targeted mailing list.

It lacks certain important features like email bounce handling.
But it should be available in the next major release:
Bounce processing #166
Bounce processing screenshot preview

Technical considerations

We used another Go application in the past: RealSender - DMARC REPORTS.
Source: dmarc-report-converter. It worked immediately with no hassle.

"PostgreSQL database management system with over two decades of development behind it, 
is now the most advanced open-source database available anywhere."
-- A Brief History of PostgreSQL -

We had a little experience of that when working in the past with Inxmail Professional server installation.
In 2017 Inxmail GmbH announced that they’ll support PostgreSQL only, dropping all the other DBs:

From 1 January 2019, we will focus on the optimal technical basis and discontinue support 
for Windows servers as well as MySQL, Oracle and MS SQL Server databases.
This means that we will only offer support for Inxmail Professional based on Linux servers and PostgreSQL.
-- Inxmail Professional licence solution: Changes to our system support

It is certainly a good choice and an investment in valuable knowledge for newbies.
Udemy online courses can help with the initial installation and maintenance of PostgreSQL.

Open source has risks: will a recent project, launched in 2019, be maintained in the future?
Nobody knows, maybe in the worst case some other developer will take care of it, but:

Email deliverability

Email Deliverability, question and answer:

hemancuso on July 12, 2019 [–]
Projects like this seem like a great idea, but deliverability seems like a big concern 
that is hard to measure unless you have a reasonable amount of experience.
What are best practices for using/selecting an ESP 
if you were to use a project like this and want to ensure reasonable deliverability?

knadh on July 12, 2019 [–]
Author here. We've been using listmonk in production at our company (regulated financial business) 
to deliver e-mail updates including regulatory ones for over 6 months. 
We host our own SMTP instances using Postal on EC2 instances and have never had any issues with deliverability. 
If it's legitimate e-mail, I don't think it's much of an issue.

We agree that sending expected communications to customers should help avoid most delivery issues.
In our experience, the larger the number, the more likely there will be drawbacks.
AWS EC2 servers are often blacklisted in Gmail - all sent messages are delivered to the Spam folder.

RealSender offers dedicated ip smtp servers,
that operate in a reliable and constantly monitored environment.

About the name

listmonk logo

goberoi on July 13, 2019 [–]
Totally random question: how did you pick the name?

knadh on July 13, 2019 [–]
I can't quite recollect, but I think the thought process was along the lines of 
"hassle free, peaceful list management".

Let’s try it

You can get a working demo installation in minutes using the docker image.
Alternatively ask RealSender a listmonk demo account.

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