Release Notes

Thunderbird Desktop

Version 91.0.2 | Released August 23, 2021

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

** Thunderbird 91 is only offered as direct download from and not as an upgrade from Thunderbird version 78 or earlier.** A future release will provide updates from earlier versions.

System Requirements: Details

  • Windows: Windows 7 or later
  • macOS: macOS 10.12 or later (macOS 11.0 for Silicon)
  • Linux: GTK+ 3.14 or higher

What’s New


Tags are now colored in mail filter editor


Preference for disabling the unread message count badge on Windows taskbar icon added: mail.biff.show_badge

What’s Changed


Context menu items related to OpenPGP and attachments are now hidden when not applicable

What’s Fixed


Creating a new account with manual setup failed


Recipient autocomplete always preferred the primary email address for a contact


LDAP performance improvements


Extensions listed on the Recommended Addons did not have a clear way to view details in a browser


Status checkmark on View > Calendar > Calendar Pane > Show Calendar Pane was reversed


mid: URLs in calendar invites did not open the linked mail message


Various theme and UX fixes

Learn What’s Next

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