Running MailHog on Debian 12

MailHog is an essential tool for intercepting emails sent by a development application. But I don't want to manage its startup and shutdown manually; it needs to be always available at system boot, especially in my dev environment. Here's how to make MailHog a proper service under Debian 12.

📦 1. Prerequisites

Check if you already have MailHog installed on your non-Dockerized Debian (Docker can also be a solution):

If not, refer to my article:

PHP / WEB DEV – Sending Emails Without SMTP

🎯 2. Objective

Launch MailHog automatically at each system boot without manual intervention, just like a good classic Debian service.

👤 3. Step 1: Create a Dedicated User

Avoid running MailHog as root. Let's create a system user with no shell or home directory:

⚙️ 4. Step 2: Create the systemd Service File

Create a mailhog.service file in the dedicated services folder:

Add the following content for our service:

💡 Here, we expose:

🔁 5. Step 3: Enable and Start the Service

Reload systemd and enable the service to start at boot:

✅ Step 4: Check That It’s Working

A quick check to verify if our service is running:

You should see an active status.

If needed, view the logs in real-time:

🚀 Result

MailHog starts automatically at each reboot. You can access the web interface at:

http://localhost:8025

Next, configure your application to send emails via localhost:1025. 🛡️ Security Bonus

If needed, you can restrict access to the web interface if your server is exposed. MailHog does not include built-in authentication, so using ufw, a password-protected NGINX proxy, or a firewall is recommended.