Installing Mailu on nixOS Latest

Mailu is a free and open-source, self-hosted email server that provides a complete solution for email hosting. In this tutorial, we will guide you through the process of installing Mailu on nixOS Latest.

Prerequisites

Before proceeding with this tutorial, ensure that your system meets the following requirements:

A fresh NixOS Latest installation
A user with sudo privileges
A domain name that will be used to configure Mailu

Step 1: Install Mailu

Open the terminal and switch to the root user by running the following command:
```
sudo -s
```
Next, we will add the Mailu repository to our system's configuration file. Open the file /etc/nixos/configuration.nix with your preferred text editor:
```
nano /etc/nixos/configuration.nix
```

Add the following lines to your configuration file:

nixpkgs.config.packageOverrides = pkgs: {
   mailu = pkgs.callPackage (builtins.fetchTarball {
      url = "https://github.com/Mailu/Mailu/archive/master.tar.gz";
      sha256 = "0586r1B6UgGmzkQJwzHm8W4LgIvqb0q3/Hp29Joa8jg=";
    }) { };
};

Save the file and exit your text editor.

Update your system's packages and repositories:

nix-channel --update nixpkgs
nix-channel --update mailu

Install Mailu:
```
nix-env -iA nixpkgs.mailu
```

Step 2: Configure Mailu

Navigate to the Mailu configuration folder:
```
cd /etc/mailu/
```
Rename the config.inc.sample.py file to config.inc.py:
```
mv config.inc.sample.py config.inc.py
```
Open the config.inc.py file using your preferred text editor:
```
nano config.inc.py
```
Update the following settings in the config.inc.py file according to your requirements:
```
DOMAIN = 'example.com'
DBPASSWORD = 'your_database_password'
```
- Replace 'example.com' with your domain name.
- Replace 'your_database_password' with a strong and secure password.
Save your changes and exit your text editor.

Step 3: Start Mailu

Start the Mailu Docker containers by running the following command:
```
docker-compose up -d
```

Verify that Mailu is running by checking its status:

docker-compose ps

If everything is working correctly, you should see the following output:

    Name                     Command                  State               Ports
---------------------------------------------------------------------------------------------------
mailu_anterm                 /bin/sh -c                Up
...
mailu_redis                  docker-                  Up      6379/tcp
mailu_rspamd                 docker-                  Up
...
mailu_ssl.dehydrated         /bin/sleep 600           Up
...
mailu_ssl.updater            /bin/sleep 3600          Up
...
mailu_sogo                   /bin/sh -c su 1000:10 ... Up      127.0.0.1:9000->80/tcp
mailu_sogo_sql               /bin/sh -c su 1000:10 ... Up
mailu_smtp                   /bin/sh -c rm -f /run ... Up      0.0.0.0:25->25/tcp
mailu_smtp-amavis            docker-                  Up      10024/tcp, 127.0.0.1:10026->10026/tcp
mailu_smtp-cluebringer       /bin/sh -c su 1000:10 ... Up      127.0.0.1:1025->1025/tcp
...

Congratulations! You have successfully installed and configured Mailu on nixOS Latest. You can now configure your mail client and start sending and receiving emails.