Thunderbird 91.0.3 is a small bug fix release

Thunderbird 91.0.3 is the third small bug fix release for the new main version of the open source email client, Thunderbird 91.

Thunderbird 91 was released just two weeks ago on August 13, 2021. The two updates that followed, fixed bugs but no security issues in the client.

The newest bug fix release, Thunderbird 91.0.3 is already available. Thunderbird includes automatic updating functionality, and most clients should pick up the new version automatically. You may select Help > About Thunderbird to display the current version and run a manual check for update; this should pick up, download and install the new version right away. The new version is also available on the official Thunderbird website for all supported operating systems as a direct download.

Thunderbird 91.0.3: release information

thunderbird 91.0.3

Thunderbird 91.0.3 is a non-security bug fix release that addresses 12 bugs found in previous versions of the email client. There is no rush to install the update, unless you are affected by one or multiple of the issues fixed in the release.

Here is the list of fixes in Thunderbird 91.0.3:

Some servers rejected Thunderbird email messages as the client was sometimes sending an unnecessary "SMTPUTF8" with the message.
Server descriptions in the account settings were not displayed correctly for non-UTF-8 servers.
Account setup UX fixes when using Exchange auto-discover.
The unread message count badge on the Windows taskbar did not update itself if unread mail was moved to the junk folder.
The date and time format of email based event scheduling was displayed in a format unreadable by humans.
Today Pane fixes:
- Filtering tasks did not work.
- The mouseover popup was not displayed for all events that were not all-day.
Folder pane toolbar did not always persist between sessions.
Linked favicons in HTML messages could override folder icons.
Unified folders did not show a message if underlying folders were removed.
The compose window attachment pane was not closed when the signing of an OpenPGP message was disabled.
Some list emails opened a "no-reply" warning when using "reply to list".