Why Choosing an Open Source Secure Email Service over Proprietary Email is a Good Idea

Today more and more organizations opt to go the open source route and email services are among them.

Why is that? In this article, we'll explore the benefits that open source offers over proprietary when it comes to email services and also introduce to you some excellent open source email clients that you can check out for yourself.

Let's get started.

What is Open Source?

First, just what is "Open Source"?

Technically, an "open source" technology is available to the public for inspection and is highly transparent.

However, such a definition of open source is too narrow and doesn't really explain the heart of it.

Open source is much more than a highly transparent technology accessible publicly. It is a free exchange of ideas and collaboration in the community. It is not just about creating a software (though that is important also), but is about creating a high-quality product that benefits the global community.

What are the Advantages of Open Source Secure Email Services over Proprietary Email Services?

Open source secure email services offer several advantages over their proprietary counterparts in any industry and email is no different.

So let's see what are the advantages when it comes to open source secure email services:

1. Product Quality Validated by the Community

This is not to say that proprietary software lacks quality or that open source is always superior in quality to it.

However, open source solutions, including secure email services, must listen much more to its community for feedback and this pushes them to adopt higher and higher security and privacy standards and to introduce new features and solve problems much faster than proprietary ones.

This is why most secure email services offer their code freely to be inspected by experts on sites like GitHub.

2. Offers a More Secure Service

Since open source code is available to anyone, usually all developers have to do is go to Github and find the code there.

Here, they can review it, find any vulnerabilities and bugs in it and fix them. This would simply not be possible with proprietary solutions where a simple patch can take months to come out.

What this leads to are bug-free software and more secure emails.

3. Freedom and Flexibility for the User

Although it's not something that happens every day, there's still a good chance that a vendor might lock-in a software (either orphaned or the one they bought).

The best example of this is PGP or Pretty Good Privacy, which is an end-to-end encryption technology developed by PGP Corporation, but in 2010, Symantec acquired the company and since then PGP encryption is their proprietary software.

However, in the meantime, PGP Inc proposed the OpenPGP standard to the IETF and thus the OpenPGP Working Group is born.

As you can see, without OpenPGP, end-to-end encryption would be far less accessible to the public.

4. They are More Cost-Effective

Open source encrypted email is not free. The companies behind them still need to make money.

However, they are usually significantly more cost-effective than proprietary email services.

This is because proprietary solutions are often dependent upon licensing fees, which can drive prices of the product up, while open source solutions don't face that problem.

In any case, the customer ends up as the winner.

Best Open Source Email Clients for Individuals and Enterprise

Next, let's take a look at some of the best open source email clients that you can check out for both individuals and enterprises, including their main features and a brief description of each.

1. Mozilla Thunderbird

Mozilla Thunderbird

Mozilla Thunderbird is probably by far the most well-known open source email client software on the market and that is for a good reason.

This software offers a multitude of useful features as well as a simple user interface and the ability to maintain several mail accounts and view them all at once or one at a time. It is also compatible with the "big three" operating systems (Windows, macOS and Linux).

Main Features:

2. Zimbra


Zimbra is an open source mail client software that works both online and in situations where the Internet connection is poor or there's simply no Internet, offline mode.

In addition, unlike many open source email clients on this list, Zimbra works on all three big operating system platforms, Windows, macOS and Linux.

Main Features:

3. Interlink


Interlink is a Mozilla-sourced community-based email client available for Windows and Linux that allows you to manage multiple accounts and access them from one place.

Main Features:

4. Claws Mail

Claws Mail

Claws Mail is a very user-friendly open source email client that works on Windows and several Linux distros including Debian, Ubuntu and Fedora that allows you to perform all your email-related tasks and manage multiple mail accounts.

It started as a fork of Sylpheed (we'll talk about it next) in 2005 (Sylpheed-Clas) and later changed the name to Claws Mail. Since 2020, both Claws Mail and Sylpheed are developed separately.

Main Features:

5. Sylpheed

Sylpheed is an open source email client for Windows, macOS, Linux and Unix that includes all the necessary features to manage your email. However, this mail client doesn't support graphics and the UI is a bit dated.

Main Features:

Looking for a Secure Email Service with End-to-End Encryption?

Open source email services are becoming increasingly popular and more and more are choosing them over proprietary email providers and clients for both business and personal usage.

CTemplar is a private email service that offers 100% audited and open-sourced code and protects user data with the top-of-the-class public key and private key combination, as well as two-factor authentication and spam protection.

We use PGP end-to-end encryption for the best protection of your email user data from third parties. In addition, our mail servers are located in Iceland, which has the best privacy laws in Europe.

We also recently released the code for our mobile apps as open source and you can check it here. This includes both mobile apps for iPhone and Android devices.

Looking for a secure end-to-end encrypted email service to protect your privacy that just so happens to be open-source? Try CTemplar and protect your privacy!