Claws Mail is a lightweight, fast, and user-friendly email client with a graphical interface based on GTK+. It is known for its extensibility (thanks to plugins), low resource consumption, and customizable flexibility. The project is aimed at experienced users but remains accessible to anyone who values efficiency and minimalism.
On March 9, 2026, version 4.4.0, which is noteworthy not only for its technical improvements but also for the symbolic date — the project turns 25 years old.
Change log:
User Interface
- Text strings and icons have been updated.
- The term 'Compose' has been replaced with 'Write'. For example: 'Write a letter', settings page 'Writing', etc.
- By default, the horizontal scrollbar in the email list is hidden unless the GENERIC_UMPC mode is used.
- A hidden setting mainwin_toolbar_always_enable_actions has been added (disabled by default). When enabled, buttons on the toolbar related to user actions remain active even if no email is selected.
- Navigation using the arrow keys on the numeric keypad (numpad) has been implemented.
- A new item has been added to the color settings: 'Emails marked for moving or deletion'. This is used when the 'execute immediately' mode is disabled.
- Compose window: When re-editing a draft, the program now prompts for confirmation to save changes made to the headers.
- Compose window: When clearing the content of the subject field, the 'Clear' button turns into a 'Remove' button, allowing you to completely remove the now-empty line.
- Folder Properties: Two new options for working with HTML have been added to the 'General' tab: 'Display HTML emails as text' and 'Display HTML emails using a plugin, if possible'.
- Folder Properties: A new option 'Show tags' has been added to control the display of message tags at the top of the email viewing area.
Plugins
- SpamAssassin: Third-party code has been updated to version 4.0.1.
- Mail Archiver: Support for Zstandard (zstd) compression has been added (requires libarchive >= 3.4.0).
- RSSyl: The default User-Agent string has been changed to ClawsMailRSSyl/$VERSION ($URL). It can be changed in the plugin settings and individually set for each feed on its properties page.
- RSSyl: A setting has been added that prevents feeds configured for manual updates from updating when all feeds are refreshed (recursively through the context menu, by timer, or at startup if enabled).
- RSSyl: Implemented saving and sending ETag and Last-Modified headers.
- RSSyl: Auto-updates are delayed if server the Retry-After header is sent. A successful manual update resets this value.
- PGP: In the NoticeView area, the message 'This key is not in your keyring' is displayed if the key is missing.
- PGP: An option has been added to automatically search for missing keys when sending encrypted messages.
- PGP: A missing key can now be obtained by clicking on the icon in the NoticeView area.
- PGP: A 'Find PGP Key' option has been added to the context menu for email addresses in the message viewer.
- Notification: For the Ayatana indicator, the ability to limit notifications to specific folders has been added.
- Notification: A 'Open Address Book' option has been added to the Ayatana indicator menu.
OAUTH2
- Configuration is now stored in a separate oauth2rc file located in the settings directory. This file allows the user to adapt to API changes from the provider or to add a completely new OAuth2 provider of their choice. Setting the protected=1 parameter inside an edited or newly created block protects it from being overwritten during Claws Mail updates.
Build system
- The minimum required version of GnuTLS has been raised to 3.4.0.
- The minimum required version of libetpan has been raised to 1.9.4.
- Support for dbus-glib has been migrated to GDBus (GIO) version 2.26 or higher and D-Bus (0.60 or higher).
- Output summary of configure has been supplemented.
Other
- A hidden setting show_contact_pic has been added. When viewing a message, if the sender is in the address book and a picture is saved for them, this option will allow that image to be displayed (if the header panel is not shown, display (X-)Face is not disabled, and enable_avatars is not set to 0). It is recommended to disable this option if there is a large address book to avoid delays in message display.
- The setup wizard now uses secure default settings.
- Various code cleanups, fixes, and improvements.
- User manuals have been updated in English, French, and Spanish.
- Updated translations: British English, Catalan, Czech, Dutch, French, German, Romanian, Slovak, Spanish, Swedish, Turkish.
- Error corrections:
- bug 4498: issues with resizing the 'About' window.
- bug 4586: display issue in three-column mode when using the PDF Viewer plugin.
- bug 4764: displaying nonexistent quotes in the email subject with line breaks in UTF-8 encoding.
- bug 4834: long email addresses in vCalendar invitations hid the attachments panel until restart.
- bug 4841: quoted-printable encoding broke text/html files with very long lines, unlike base64.
- bug 4846: in toolbar settings, always show icon preview on the button.
- bug 4848: new icon in the Ayatana tray did not display when new messages were present.
- bug 4850: displaying an error dialog when there is an error fetching mail (translation).
- bug 4852: canceled messages contained the header Approved.
- bug 4854: disabled line wrapping did not work when using an external editor.
- bug 4856: build error with gettext 0.24.
- bug 4863: minor interface inconsistency in account settings.
- bug 4882: IMAP could not use a client certificate with a passphrase.
- bug 4887: Dillo processes did not terminate when the HTML message was no longer viewed.
- bug 4893: Clamd plugin did not check mail.
- bug 4897: 'small screen' mode: crash when exiting the message list view after deleting all messages in the folder.
- bug 4898: when entering a folder, the message list did not scroll to the selected email.
- bug 4902: memory leak in spam_report plugin.
- bug 4930: duplicate signature flag removed from MimeView.
- bug 4931: memory leak fixed in summary_set_header.
- Fixed an issue that caused viewing emails in a separate window not to mark them as read when the preview pane was hidden.
- Fixed build error with the litehtml plugin on Windows.
- 'Save email as...' from a separate view window saved what was selected in the email list, not what was open in the view window.
- Fixed a sequence of actions leading to a crash when the view window was closed.
- Fixed a header panel issue where a very long header value pushed the MIME icon panel out of the visible area.
- No more attempts to remove the tag from the list occur when the input focus is on the tag editing field.
Source: linux.org.ru
