Download Mozilla Thunderbird 91.4.1

The Mozilla Foundation has released version 91.4.1 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

• Attachments that should open in Thunderbird, such as ICS attachments, offered to save the file instead
• Saving attachments from IMAP accounts where usernames contained special characters failed
• Temporary files created for forwarded attachments sometimes had the wrong extension
• S/MIME signatures were shown as invalid by Outlook
• URL input boxes on content tabs erroneously displayed a search glass icon on macOS
• Message bars (such as content blocking) did not use high contrast theme colors
• Some messages with autocrypt headers loaded slowly, causing Thunderbird to hang
• Server hostnames were cut-off in the account manager
• Account Setup did not support non-ASCII characters in passwords
• Account Setup did not always retain set values
• Virtual folders did not retain folder selection when a folder name contained non-ASCII characters
• Messages saved as “html” or “eml” did not include message headers
• “Private web page” field was not included when exporting a contact to a vCard
• Addons were still active after restarting Thunderbird in troubleshooting mode with “disable all addons” checked
• FileLink attachments did not always display the FileLink provider’s icon
• FileLink privacy notifications persisted in the compose window after removing all FileLink attachments
• “Loading” icon remained after a FileLink upload failed
• Lengthy event names for multiday events did not wrap
• Various theme and UX improvements
• Various security fixes