Foundry376/Mailspring 1.24.0 on GitHub

1.24.0 (9/12/2026)

Note: The Flatpak version of Mailspring now uses Portal for secret storage, and you may be prompted to re-authenticate accounts after upgrading.

Note: Mailspring now requires macOS 13 (Ventura) or later, because Chromium has dropped support for macOS 12. Windows and Linux system requirements are unchanged.

Features:

Added support for dragging threads into the composer to attach them as .eml files. (#2800)
Added subject line support to email templates. (#2794)
In the calendar, dragging an event now converts between all-day and timed. (#2819, #2812) Thanks @manilabui!
Added an MCP get_attachment tool so local agents can view mail attachments. (#2807) Thanks @ahmedwalid05!
On Windows, Mailspring now recovers from GPU-related renderer crashes that happen before the window loads by relaunching with hardware acceleration disabled. Thanks @ejbiker93ss!

Bug Fixes:

Mailspring now falls back to legacy TLS settings when the handshake is rejected, and surfaces a suggestion when it does. (#119)
Fixed crash safety, XML escaping, and log hygiene issues in the sync engine. (#122) Thanks @brhellman!
Fixed synchronization with NetEase IMAP servers. (#121) Thanks @aixia715!
Fixed recurring meetings whose series started years ago not appearing in the calendar. (#2845) Thanks @brhellman!
On Linux, EROFS, EIO, ENOSPC, and EBADF are now swallowed alongside EPIPE in the stdout/stderr error handler. (#2789)
Plain text messages are no longer inverted in dark mode, causing black-on-dark-gray text.
Messages with stylesheets in the HTML <head> region now render with the styles intact.- Fixed a crash in the thread list context menu for threads with no participants. (#2839)
Fixed a composer crash when removing a link mark with no active mark present. (#2802)
Fixed a composer crash when applying a signature to an empty document. (#2804)
Fixed a composer crash when backspacing near an unpaired UTF-16 surrogate. (#2808)
Fixed a composer crash from an unset Slate selection point. (#2787)
Fixed a crash when the custom-fonts plugin activated during boot. (#2785)
Fixed a ChangeLabelsTask assertion failure when removing search results. (#2816)
Fixed a TaskQueue crash when queries loaded out of order. (#2786)
Fixed an uncaught "Unknown button clicked" crash in the config load-error dialog. (#2798)
Fixed all-day events losing or gaining a day across edit, drag, and recurring paths, including near DST transitions. (#2799, #2805, #2806, #2810) Thanks @manilabui!
Fixed resizing recurring events when applying the change to all events. (#2814) Thanks @manilabui!
Fixed calendar deletion and blocked edits on read-only calendars and past events. (#2797) Thanks @manilabui!
Fixed pasted text colors and line spacing on Windows. (#2796) Thanks @Mylosis!
Fixed scrollbars appearing in the inbox-zero animation. (#2821) Thanks @m-salman-afzal!
Fixed timed calendar events at midnight and across DST day boundaries rendering in the wrong day column or not at all. (#2847) Thanks @manilabui!
Fixed timed calendar events sitting off their gridlines on DST days. (#2852) Thanks @manilabui!
Fixed a timed event losing its time of day when its edge was dragged in month view. (#2858) Thanks @brhellman!
Fixed the calendar view jumping when an event was selected for the first time. (#2854) Thanks @brhellman!
Fixed the day/week calendar grid not scrolling to the end of the day in short windows. (#2851) Thanks @manilabui!
Fixed every calendar invitee being underlined as a malformed address. (#2844) Thanks @brhellman!
Fixed "Refresh Calendars" not actually syncing calendars. (#2853) Thanks @manilabui!
Fixed a TypeError when creating or editing calendar events with an organizer or attendees. Thanks @ejbiker93ss!
The calendar now syncs immediately after you RSVP to an invitation. Thanks @ejbiker93ss!
Fixed the mini month view's today marker not advancing past midnight. Thanks @ejbiker93ss!
Fixed Outlook-style read/unread keyboard shortcuts on Windows. (#2849) Thanks @ejbiker93ss!
Fixed "Reset Theme" after a theme compile error not recovering when the failing theme was set as the light or dark theme. Thanks @ejbiker93ss!
Fixed contact email addresses with surrounding whitespace failing validation or being sent as malformed recipients. Thanks @ejbiker93ss!
Mailsync startup failures now report the actual reason instead of "an unknown error has occurred". (#2827) Thanks @brhellman!
On macOS, Quick Look thumbnail generation now times out so hung qlmanage processes can't accumulate. (#2862) Thanks @nitay!
Fixed an unhandled promise rejection when opening identity links while signed out. (#2861)
Fixed the system tray icon not appearing on Linux when Mailspring launched before the desktop's tray host was ready, and when running in the Snap or Flatpak sandbox. (#2863, #2825)
Files copied from Finder, Explorer, or a Linux file manager and pasted into the composer now attach under their original filename instead of "Pasted File".

Improvements:

Selected calendar events now stay selected and scroll into view when switching views. (#2815) Thanks @manilabui!
You can now drag across past events in the calendar to create a new event. (#2809) Thanks @manilabui!
HTML signatures can now be pasted into the "Raw Signature" box.
On Linux, autostart now uses XDG Desktop Portals when running inside Flatpak. (#2838) Thanks @LinusDierheimer!
The key manager now uses the async safeStorage API. (#2823) Thanks @LinusDierheimer!
Removed the legacy dark-theme email inversion; the "Match app theme" email render mode is gone and email bodies now default to light mode. (#2850) Thanks @ejbiker93ss!

Localization:

Added Swedish desktop and integration labels. (#2837) Thanks @yeager!
Updated the Czech translations. (#2855) Thanks @tomo90!
Completed the missing Traditional Chinese strings. (#2790) Thanks @nrps9909!
Updated the Hebrew translations and added Hebrew to the list of human-verified languages. (#2801) Thanks @omeritzics!
Updated translations of new strings and made minor corrections. (#2784) Thanks @Impostor0729!

Developer:

Updated Electron from 41.7.2 to 44.3.0 (Chromium 152, Node.js 24.20). (#2818, #2825) Thanks @wrench-exile-legacy and @LinusDierheimer!
Migrated to Electron 44's promise-based clipboard API; the module is no longer available in renderer processes.
Added Playwright coverage for composer paste (text, HTML, images, and copied files) and clipboard writes; window.eval is enabled under the Playwright harness so page.evaluate works.
Upgraded tar to 7.5.19 to address CVE-2026-59873. (#2811) Thanks @anupamme!
Switched app/package.json from resolutions to overrides. (#2822) Thanks @LinusDierheimer!
Fixed the three type errors that were keeping CI red. (#2829) Thanks @brhellman!
reportError() now captures a real stack for stackless inputs. (#2828)
Errors thrown by community plugins are no longer reported to Sentry. (#2783)
Uncaught shell.openExternal rejections now capture the caller stack. (#2788)
ContextifyScript compile errors with no first-party frames are no longer reported to Sentry. (#2859)
On Linux, newer versions of sqlite3 are now built with clang-15.
Added a Claude Code hook that lints edited TypeScript files.