Download Mozilla Thunderbird 91.4.0

The Mozilla Foundation has released version 91.4 of Thunderbird. Thunderbird is an open source client for e-mail and newsgroups, with features such as support for various mail and news accounts, a spam filter, spell checker, and a customizable appearance. In version 91 has included a warning when an email is sent to a potentially non-existent address, or if there are too many addresses on the public address line. There is also support for CardDAV and there is a native client for a Mac equipped with an Apple Silicon processor. The following changes and improvements have also been made in this release:

Fixes

• IMAP startup performance improved for accounts with a multitude of folders
• Thunderbird failed to send messages when configured to use an IPv6 SMTP server by IP address (instead of a hostname)
• Forwarding messages with attachments sometimes failed
• Printing multiple messages at once was not possible
• Non-utf8 news groups were not supported
• Thunderbird stalled after sending a message with NNTP and SMTP recipients
• Using Thunderbird with multiple language packs caused high RAM and CPU use and sluggish performance
• Clicking a “mailto:” started the composer with the default sending identity instead of a configured alternate
• Drag and dropped text into a plain text message in the compose window was handled inconsistently
• FileLink messages did not display correctly when viewed in Outlook
• In account setup, after selecting an extension provided protocol, it was not possible to create an IMAP/POP account
• Multiday selections were not cleared when changing week viewed
• When creating a new event by clicking and dragging the mouse to create a box, the view did not auto-scroll after reaching the bottom
• Calendar Invitation Panel did not scroll when multiple invitations were pending
• Calendar print dialog did not have a cancel button
• Various security fixes