Release Notes

Thunderbird Desktop

Version 91.3.0 | Released November 3, 2021

Check out the notes below for this version of Thunderbird. As always, you’re encouraged to tell us what you think, ask for help, or file a bug in Bugzilla.

For more on all the new features in Thunderbird 91, see New in Thunderbird 91.0.

System Requirements: Details

  • Windows: Windows 7 or later
  • Mac: macOS 10.12 or later
  • Linux: GTK+ 3.14 or higher

What’s Fixed

fixed

Default mail headers were set incorrectly when the value contained a colon (:)

fixed

Thunderbird did not send the QUIT command when closing an SMTP connection

fixed

Mail tabs could not be closed using the context menu

fixed

"Print" context menu was still shown when no message pane was displayed

fixed

Windows tray icon did not reappear after restarting Windows Explorer

fixed

Compose window attachment drag and drop fixes

fixed

Various macOS stability improvements

fixed

Drag and Drop area for file attachments on Windows was incorrect

fixed

CardDAV address books without a name did not work

fixed

Thunderbird tried to refresh disabled and manual-only calendars when the network state changed from offline to online

fixed

Various Calendar event dialog fixes

fixed

Various security fixes

Learn What’s Next

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