Easily Install and Run Postal Email Platform on Ubuntu VPS (5 Minute Guide)

This article provides a guide for how to install and run Postal email platform on Ubuntu VPS.

Step-by-Step Guide to Install and Run Postal Email Platform on Ubuntu VPS

Postal is an open-source mail server for sending and receiving emails, designed for businesses and developers. This guide outlines the step-by-step process to install and configure Postal on an Ubuntu VPS.

READ ALSO: Optimizing Your Hosting Experience: The Advantages of Ubuntu VPS Servers for Your Business

Prerequisites

Before you begin, ensure the following:

1. Ubuntu VPS: Use a fresh installation of Ubuntu 20.04 or later.
2. Minimum VPS Specifications:
   • At least 4GB RAM.
   • 2 vCPUs.
   • 20GB disk space (more is better for logs and emails).
3. Root Access: SSH access with a user that has sudo privileges.
4. Domain and DNS: A domain name with DNS records configurable.

VPS Server Environment

For this guide, we will be using the following server environment:

• Plan: KVM-SSD-8
• CPU: 2 Core
• RAM: 8 GB ECC
• Disk: 128 GB SSD
• Network: 1Gbps
• 1 IPv4 (Public)
• /64 IPv6 (Public)
• Operating System: Ubuntu 22.04 LTS
• View more: Ubuntu VPS

How to Install and Run Postal Email Platform on Ubuntu VPS

To install and run Postal email platform on Ubuntu VPS, follow the steps provided:

1. 1. Update and Upgrade the System

      sudo apt update && sudo apt upgrade -y

      This ensures your system is up to date and ready for installation.

   2. Install Dependencies

      Install necessary tools and libraries:

      sudo apt install -y ca-certificates curl git jq

      Install Git & installation helper repository:

      git clone https://github.com/postalserver/install /opt/postal/install sudo ln -s /opt/postal/install/bin/postal /usr/bin/postal

   3. Install MariaDB (10.6+)

      Postal requires a database engine to store all email and other essential configuration data. You will need to provide credentials that allow full access to create and delete databases as well as having full access to any databases created. Postal will provision a database automatically for each mail server that you create.

      Install MariaDB on your Ubuntu VPS:

      sudo apt install mariadb-client-core-10.6
      

      You can run MariaDB in a container, assuming you have Docker, using this command:

      docker run -d \
      --name postal-mariadb \
      -p 127.0.0.1:3306:3306 \
      --restart always \
      -e MARIADB_DATABASE=postal \
      -e MARIADB_ROOT_PASSWORD=postal \
      mariadb

      • This will run a MariaDB instance and have it listen on port 3306.
      • Be sure to choose a secure password. You’ll need to put this in your Postal configuration when you install it so be sure to make a (secure) note of it.

   4. Configuration

      Before you can start Postal, you’ll need some configuration. The repository you cloned includes a tool to automatically generate some initial configuration files.

      Run the command below and replace postal.yourdomain.com with the actual hostname you want to access your Postal web interface at. Make sure you have set up this domain with your DNS provider before continuing:

      postal bootstrap postal.yourdomain.com
      

      This will generate three files in /opt/postal/config:

      • postal.yml is the main postal configuration file
      • signing.key is the private key used to sign various things in Postal
      • Caddyfile is the configuration for the Caddy webserver

      Once generated, you should open up /opt/postal/config/postal.yml and add all the appropriate values for your installation (database passwords etc…).

      Note that the docker setup mounts /opt/postal/config as /config so any full directory paths mentioned in postal.yml will likely need to start with /config and not /opt/postal/config

   5. Initializing the Database

      Run the following commands to initialize the database and create tables:

      postal initialize postal make-user

   6. Setup Caddy

      docker run -d \ --name postal-caddy \ --restart always \ --network host \ -v /opt/postal/config/Caddyfile:/etc/caddy/Caddyfile \ -v /opt/postal/caddy-data:/data \ caddy

      Install Bundler (Ruby dependency manager):

      gem install bundler

      Run Postal setup:

      postal bundle /opt/postal/app/vendor/bundle postal initialize-config

   7. Configure DNS for Postal

      Set up DNS records for your domain:

      • A Record: postal.example.com → VPS IP
      • MX Record: example.com → postal.example.com
      • SPF Record: v=spf1 a mx include:postal.example.com ~all
      • DKIM Record: Add the DKIM public key (provided in Postal admin UI).
      • Reverse DNS: Ensure the PTR record for your VPS IP resolves to postal.example.com.

   8. Configure Postal

      Edit the Postal configuration file:

      nano /opt/postal/config/postal.yml
      

      Set:

      • web.host: The domain you set up (e.g., postal.example.com).
      • dns.hostname: The hostname for DNS records.
      • smtp.listen_address: Leave as 127.0.0.1 or customize if needed.

      Save and exit.

   9. Start Postal

      Run the following command to start Postal:

      postal start

      To check Postal status:

      postal status

   10. Access the Postal Web Interface

       Open your browser and navigate to http://postal.example.com. Log in with the default admin credentials generated during setup. Update your password immediately.

       Enter your Postal credentials created during installation. Then access the postal platform.
       

   11. Test Email Sending

       • Log into the Postal web interface.
       • Configure a mail server (e.g., SMTP endpoint).
       • Test by sending emails.

Troubleshooting

1. Logs: Check logs for errors:

   postal log

2. Firewall: Ensure required ports are open (e.g., 80, 443, 25, 587).
3. DNS: Verify DNS settings using tools like dig or online DNS checkers.

Conclusion

By following these steps, you’ll have a fully functional Postal Email Platform running on your Ubuntu VPS. Ensure you monitor system resources and apply updates regularly for optimal performance and security.