Claws Mail

Claws Mail.

Claws Mail is a free and open-source, C/GTK+-based e-mail client, which is both lightweight and highly configurable.

Claws Mail runs on both Windows and Unix-like systems such as Linux, BSD, and Solaris.

It stores mail in the MH mailbox format.

Plugins allows you to to read HTML mail, but there is none to compose HTML messages.

Claws Mail is also a News client and RSS aggregator.

Latest version:  3.19.1 / 4.1.1, on 20 October 2022.

License: GNU/GPLv3

Features supplied via plugins:

• Search and filtering, optionally via Perl and Python scripting.
• Security (GPG, SSL, anti-phishing).
• Anti-spam (SpamAssassin, Bogofilter).
• Per-folder preferences.
• Optional external editor.
• Templates for messages.
• Themes support, customisable toolbars, X-Face support, foldable quotes.
• Viewers for HTML mail (Dillo, Gtkhtml2, Fancy (WebKit)), TNEF attachment parser, PDF viewer.
• Various notification plugins, e. g. trayicon and LED handler.
• Archiving, import/export from standard formats.
• Support for Mbox mailbox format.
• Calendaring with events as kind of messagess.

How to install via a terminal window:

sudo apt-get install claws-mail

Press Enter and follow the setup instructions.

NOTE: This e-mail client had less interest, compared to the others listed, while looking over statistics.