Updated 27-Aug-2026
Note, Claws has some ugly bits that just don't go away. I'm currently trying out Aerion email client, which looks quite promising.
Claws is a 25-year-old email client that is still getting updates. It started as a fork of Sylpheed, and is now using GTK3. The look is a bit old-fashioned, but it does have a reasonable dark mode, and is good at managing IMAP messages and folders.
Claws Mail Features
- Great dark mode (looking at you Kmail)
- Easy to configure multiple IMAP mailboxes
- A joy to view HTML mail in text (still with working URLs)
- Can drag messages from one IMAP mailbox to a different IMAP mailbox
- Kmail could do this but Geary could not
- Can configure toolbars extensively
- For example creating an archive button
- Up-to-date apt repositories
sudo apt install claws-mail
Claws Mail Antifeatures
- No Universal Inbox concept
- Have a bit of configuring to do to get everything working (but quite extensible)
- No easy way to toggle between text and html email formats.
- Weak calendar integration (no viewing as a calendar widget, though appointments are supported)
Claws plugins
The Claws Plugins are in a variety of places:
sudo apt install claws-mail-plugins -t trixie-backportsgets you bogofilter, php, mime, and spamassassin pluginssudo apt install claws-mail-extra-plugins -t trixie-backportsgets you a bunch if not the vast majority of plugins- bsfilter, claws-mail-managesieve, clamav, claws-mail-multi-notifier, clamav-base, claws-mail-newmail-plugin, clamav-freshclam, claws-mail-pdf-viewer, claws-mail-acpi-notifier, claws-mail-perl-filter, claws-mail-address-keeper, claws-mail-python-plugin, claws-mail-archiver-plugin, claws-mail-spam-report, claws-mail-attach-remover, claws-mail-tnef-parser, claws-mail-bsfilter-plugin, claws-mail-vcalendar-plugin, claws-mail-clamd-plugin, dillo, claws-mail-dillo-viewer, libclamav12, claws-mail-fancy-plugin, libfltk1.3t64, claws-mail-fetchinfo-plugin, libpython3-all-dev, claws-mail-keyword-warner, python3-all, claws-mail-litehtml-viewer, python3-all-dev, claws-mail-mailmbox-plugin
- Most of the other plugins are listed here
- But they are mostly found in Debian apt repositories listed here. Note: use
-t trixie-backportsin getting these installed or some weird stuff happens.
- But they are mostly found in Debian apt repositories listed here. Note: use
- Impossible to find the
vfolderplugin, though there are signs it was merged into the core. Still, no clue as to how to set it up so Universal Inbox is still just a dream.
Claws mail themes
sudo apt install claws-mail-themes
Claws signatures
I prefer to create the sig files for each account, but disable them auto-added (in Configuration > Edit accounts > Edit > Write). Then I edit the templates to include them. This allows me to place them where I want them to be and not where I do not want them to be.
- Location: Configuration > Messages > Write > Template
New message template
%cursor
%as
Reply template
%cursor
%as
On %d
%f wrote:
%q
Additional resources
- Claws Mail user manual is quite detailed
- Claws Mail tools mainly perl scripts that do cool things
- Claws Mail documentation not the same as the user manual above