Claws Mail is an open source email client with more bite than most. It’s not quite as slick as rivals like Mailbird Free, but whatever it lacks in polish it makes up for in speed and flexibility. It’s made primarily for Linux, but there’s also a port for Windows users, with an experimental 64-bit version.

Claws Mail is packed with tools to help you tame even the most unwieldy of inboxes, including quick importing of contacts, a fast message cache system, the ability to download all attachments in an email at once, and a powerful quick search tool.

That’s not all; Claws Mail is an open-source project, so anyone can use its code to make plugins to expand its capabilities. Many users have done just that and spent their free time building include tools that you never realized you needed, like one that strips attachments out of emails automatically and another that alerts you to new emails by illuminating lights on your laptop. 

Setting up your accounts in Claws Mail isn’t quite as straightforward as it is in Mailbird Free (which just requests your webmail login details), but it’s not excessively complicated. 

Importantly, Claws Mail doesn’t place a limit on the number of email accounts you can add, making it a great choice for anyone with lots of personal and work inboxes to manage.

Claws Mail looks simple at first, and the basic features are all self-explanatory, but spend a little time delving into its menus and you’ll find dozens of powerful timesaving tools like advanced message filtering.  You can create your own filters from scratch, including any combination of flag color, sender, age, phrase and many more. Custom filters can be applied globally to all messages, or limited to specific folders.

Another of Claws Mail’s best features is the threat-scanning courtesy of open source antivirus engine ClamAV via the Clam AntiVirus plugin. Emails are one of the most common vectors for malicious software, so this is a very welcome extra layer of protection for your inbox that won’t conflict with your existing antivirus software.

The Key Features of Claws Mail

Claws Mail has tons of useful features that make it one of the best email clients on the market today.

Let’s go over some of them:

1. Open-Source-Based

Before going into detail as to why this is a great feature, let’s clarify what open-source means.

An open-source software application is one that allows its source code — what it’s essentially built on — to be readily accessible to anyone who wants it. As a result, anyone with the source code can modify the software to fit their own needs and preferences!

With the Claws Mail Windows email client, you can add as many custom integrations and settings as you want. These can range from incorporating Linux package codes like command sudo and starttls or even running it on any Linux distros you like!

This way, you’ll be able to create your own compatibility and functionality for your app.

2. Filtering Capabilities

When you receive tons of emails on a daily basis, it’s important to be able to organize them effectively. With Claws Mail, you’ll be able to do that easily.

You can add as many custom filters to your inbox as you like, such as sorting emails according to sender or even content. This way, you’re not limited to the traditional Spam, Draft, and Trash folders.

Also, as you’re able to organize your emails effectively, you won’t have to worry about emails getting jumbled up and dealing with a messy inbox!

3. Reliability & Updates

Another important benefit of Claws Mail is reliability. As the software is constantly updated, any lingering issues are usually dealt with swiftly, and you’ll be back to business in no time.

Additionally, due to these constant service updates, Claws Mail is a very fast app when it comes to loading and handling emails.

4. Plugins

In addition to allowing you to add any custom package you like, Claws Mail has a standard set of useful plugins such as:

  • RSS news reader plugin to deal with RSS feeds in the email client
  • MBox handler plugin to manage message files stored in that format
  • SpamAssassin plugin to ensure you can tackle any spam mail

With these, you’ll be able to add a ton of functionality to Claws Mail from the moment you download it.

5. Completely Free

Another Claws Mail calling card is that it’s completely free.

There’s no paid variant of the software that will give you any additional functionality — you get everything it can offer you for free.

You can install Claws Mail via Ubuntu Software Center or follow our install and setup guide.