In this tutorial, you will learn how to generate a CSR code and install an SSL Certificate on Qmail. You will also discover a few interesting facts about Qmail, and where to buy the most affordable SSL certificates for the mail transfer agent.

If you’ve already generated the CSR code and received the SSL certificate in your email inbox, jump straight to the installation instructions.

Generate a CSR code for Qmail

CSR stands for Certificate Signing Request, a block of encoded text with information about your domain and company. Every SSL applicant must generate the CSR and submit it to the Certificate Authority for validation. The quickest and easiest way to generate the CSR is via an external tool such as our CSR Generator.

Another way is to do it with help of the OpenSSL utility. Use the shell commands below to create your CSR:

  1. Connect to your server
  2. At the prompt type: openssl req -new -newkey rsa:2048 -nodes -keyout your_domain_name.key -out your_domain_name.csr
    This command will create two files on your system:

  3. Next, you have to provide information about your organization and the domain name you want to secure:
    • CN (Common Name): the FQDN (fully-qualified domain name) you want to secure. For instance,
    • O (Organization): the full legal name of your company
    • C (Country Name): the two-letter code of your country
    • ST (State): the state where your company is located
    • L (Locality/City): the city where your company is registered.

Your CSR and Private Key files will be saved to the current directory. Use a text editor to open the CSR. Copy and paste the entire block of text (including the BEGIN and END tags) into the ‘CSR’ field of your order form. For more information about how to protect your Private Key, check this article.

Install the SSL certificate on Qmail

After your Certificate Authority validates your SSL request, you will receive the installation files via email. Download the archived folder and extract its contents on your system. Follow the instructions below to complete the installation:

  1. Create a combined .pem certificate file. If you’re not familiar with SSL files and formats check this complete guide.
  2. Open a text editor of your choice  and paste the contents of each key/certificate one after another in the following order:
    • The private key
    • The primary certificate
    • The intermediate certificate
    • The root certificate

Make sure that you include the begin and end tags of the key and each certificate including the dash lines. Here’s how your file should look like:


(Your Private Key)



(Your Primary SSL certificate)



(Your Intermediate certificate)



(Your Root certificate)


  1. Name your combined file and save it with .pem extension.
  2. Move this file to your /var/qmail/control/ directory.
  3. To enable the SSL certificate on Qmail, rename your file to that already in use on the server, or modify the server configuration file to point to the newly created certificate
  4. Restart your Qmail server.

Congrats, you’ve successfully installed your SSL certificate on Qmail.

Test Your SSL installation

After you install an SSL Certificate on Qmail, your next step is to check your new cert for potential errors and vulnerabilities. Use these SSL tools for instant scans and reports on the state of your SSL Certificate and its configuration.

Qmail history

Qmail is a mail transfer agent (MTA) that runs on Unix. It was written by Daniel J. Bernstein in 1995 as a more secure replacement for the popular Sendmail program. Qmail was initially a license-free software, but in 2007 it was released to the public domain. The software is still available and widely used. Here’s Qmail’s release history:

  • Qmail – Final release 1.03 / June 15, 1998
  • Netqmail -Final release 1.06 / November 30, 2007
  • Notqmail – Final release 1.08 / May 20, 2020
  • s/qmail – Final release 4.1.10 / August 1, 2021

Where to buy the best SSL Certificate for Qmail?

The best place to buy an SSL Certificate for Qmail is from an SSL vendor such as SSL Dragon. Our prices are the lowest on the market, but there are even more benefits

We offer regular discounts and exclusive deals on all our SSL certificates, but above all, impeccable customer support. All our certs are compatible with Qmail. We offer the following types of certificates:

SSL Dragon takes care of your sensitive data security, so your website or business can succeed online!

If you find any inaccuracies, or you have details to add to these SSL installation instructions, please feel free to send us your feedback at [email protected] Your input would be greatly appreciated! Thank you.