How to Install Mailman 3 on a Debian 10 Server.

This document is a How-To on installing Mailman 3 on a Debian 10 server. The server environment will include Debian 10, NGINX, Let's Encrypt, Postfix, and PosgresDB.

Prepare Server Environment

1. Create a VPS running Debian 10. I recommend something from Digital Ocean or Linode. The server should be a minimum of 1 CPU and 2 Gigabyte of Memory. 25-50 Gb of storage should be sufficient.

2. Log into the server as root.

$ ssh root@your_server_ip

3. Create a New User: mailman

# adduser mailman

You will be asked some questions about this new user when running the above command. Please make sure you use a strong password for mailman as it will be typically known that any server running Mailman 3 will have a mailman user setup on it.

4. Let's go ahead and grant the 'mailman' user SUDO privileges while logged in as root:

# usermod -aG sudo mailman

5. I recommend setting up a basic firewall to tighten up security on this Mailman 3 server. UFW is one that can be installed on a Debian 10 server:

# apt update
# apt install ufw

Once UFW is installed, you need to make sure you allow the various applications that Mailman 3 will be using through UFW. Some of these applications are the following: OpenSSH, Nginx Full, and Postfix.

So here is an example of what to do immediately after you install UFW:

# ufw app list

Output
Available applications:
 . . .
 OpenSSH
 . . .

This tells us what available applications we can configure UFW to allow. So let's add OpenSSH to UFW:

# ufw allow OpenSSH

Now we can enable UFW:

# ufw enable

You can see what is allowed through the UFW firewall by running the following command:

# ufw status

Output
Status: active

To             Action   From
--             ------   ----
OpenSSH          ALLOW    Anywhere
OpenSSH (v6)     ALLOW    Anywhere (v6)

Webserver Installation: NGINX

1. Both Django, Postorius, and Hyperkitty requires a web server. So let's install NGINX.

apt install nginx

2. Now that Nginx is installed, we need to allow it through the UFW Firewall.

# ufw allow 'Nginx Full'

Let's verify the change.

# ufw status

Output
Status: active

To                         Action      From
--                         ------      ----
OpenSSH                    ALLOW       Anywhere                  
Nginx HTTP                 ALLOW       Anywhere                  
OpenSSH (v6)               ALLOW       Anywhere (v6)             
Nginx HTTP (v6)            ALLOW       Anywhere (v6)

3. Let's make sure Nginx is running.

# systemctl status nginx

Output
● nginx.service - A high performance web server and a reverse proxy server
   Loaded: loaded (/lib/systemd/system/nginx.service; enabled; vendor preset: enabled)
   Active: active (running) since Wed 2019-07-03 12:52:54 UTC; 4min 23s ago
     Docs: man:nginx(8)
 Main PID: 3942 (nginx)
    Tasks: 3 (limit: 4719)
   Memory: 6.1M
   CGroup: /system.slice/nginx.service
           ├─3942 nginx: master process /usr/sbin/nginx -g daemon on; master_process on;
           ├─3943 nginx: worker process
           └─3944 nginx: worker process

If your output has Active: active (running) then you are good to go.

With Nginx confirmed to be running you should be able to access it via your server' IP address:

http://your_server_ipaddress

Learning how to manage the Nginx processes and setting up server blocks is beyond the scope of this How-To. However feel free to contact me if you would like for me to edit this document and add those instructions into this particular section.

Securing Your Nginx Installation: Let's Encrypt

1. The first step in securing Nginx is to install Certbot. This means first installing the dependencies for Certbot.

# apt install python3-acme python3-certbot python3-mock python3-openssl python3-pkg-resources python3-pyparsing python3-zope.interface

Now we are ready to install Certbot:

# apt install python3-certbot-nginx

Normally you would need to allow SSL traffic through the AFW firewall but we have already done previously in this how-to so we can continue on.

2. The next step is to fetch a SSL certificate for your Mailman 3 list domain name. This how-to assumes you know how to add a server block to Nginx. I keep my server blocks in /etc/nginx/conf.d/. You will need to make sure you have a server block setup already for your domain name before proceeding.

To obtain a SSL certificate for your domain name run:

# certbot --nginx -d your_domain

Certbox will go through its motions. At the end it is going to ask you whether you want to redirect all HTTP traffic to HTTPS. Choose 2 if yes which is what I recommend doing.

That's it! We are now ready to install Postfix because after all, Mailman 3 needs to send out mail.

Mail Server Installation: Postfix

1. Ok, we are now ready to install Postfix. The first thing we do here is install mailtuils:

# apt install mailutils

Now we install Postfix:

# apt install postfix

2. Now you will be presented with an interactive dialogue:

General type of mail configuration: Internet Site

System Mail Name: server hostname

3. Let's configure Postfix now. Open the main Postfix configuration file:

# nano /etc/postfix/main.cf

4. Make sure inet_interfaces is set to all:

inet_interfaces = all

5. Now let's set myhostname and mydestination:

myhostname = server_hostname
mydestination = $myhostname, localhost.$myhostname, localhost

Save and close the file.

6. Time to apply the changes:

# systemctl restart postfix

7. You can test your postfix installation by doing the following:

# echo "This is the body of the email" | mail -s "This is the subject line" your_email_address

8. The final step is to allow postfix through the firewall:

# ufw allow postfix

Now you have a working SMTP server and it's time to install and set up a database server for Mailman 3.

Database Server Installation: Postgres

1. So, the first step is to install several packages, some of these are needed for later steps:

# apt install python3-pip python3-dev libpq-dev postgresql postgresql-contrib curl

2. Now that PostgreSQL is installed, let's create the Mailman database and user. First let's open up a Postgres session by typing the following:

# sudo -u postgres psql

Now let's create the Mailman database:

postgres=# CREATE DATABASE mailman;

Now let's create the Mailman user:

postgres=# CREATE USER mailman WITH PASSWORD 'secure-password';

The following is recommended for setting up a Django project which is what is needed for the installation of Postorius and Hyperkitty:

postgres=# ALTER ROLE mailman SET client_encoding TO 'utf8';
postgres=# ALTER ROLE mailman SET default_transaction_isolation TO 'read committed';
postgres=# ALTER ROLE mailman SET timezone TO 'UTC';

The timezone part can be customized to reflect your geographical setting.

The last step is to give access to the mailman user to administer the mailman database:

postgres=# GRANT ALL PRIVILEGES ON DATABASE mailman TO mailman;

To finish this section out, exit the PostgreSQL prompt:

postgres=# \q

Setup of a Python Virtual Environment

Let's make sure we have Python 3 installed.

# apt install python3 python3-venv

Now we are going to be using a virtual environment to install Mailman 3. So let's install that too:

# apt install virtualenv python3-virtualenv

Installation of Potentially Needed Applications

Now that we have a working web, email and database server it’s time to install a number of potentially needed applications. Install the following applications as root:

# apt install ruby-sass
# apt install memcached
# apt install fail2ban
# apt install gettext

Setup Directories and Files for Mailman 3

Ok, now we need to create some directories and files.

Directories:

# mkdir -p /opt/mailman/mm/bin/ 
# mkdir /opt/mailman/mm/var/

Files:

# touch /opt/mailman/mm/init.py (empty)

# touch /opt/mailman/mm/mailman.cfg sample

# touch /opt/mailman/mm/mailman-hyperkitty.cfg sample

# touch /opt/mailman/mm/settings_local.py sample

# touch /opt/mailman/mm/settings.py (copy of the mailman-suite settings.py file but with DEBUG = False)

# touch /opt/mailman/mm/urls.py sample

# touch /opt/mailman/mm/wsgi.py sample

# touch /opt/mailman/mm/gunicorn.conf sample

Create and Enter Virtual Environment

Installation of Additional Applications via PIP

Setup Startup Scripts