Thunderbird 91.1.2 is out

The most popular freeware mail client, Thunderbird, has reached version 91.1.2. Today's update is a minor release with comes with just one change and a number of fixes. Here are the changes.


The open source mail and RSS reader contains all the essential features for reading and managing your emails. It also supports add-ons, that extend its functionality, add themes and custom icons. Thunderbird is an open source project, which means anyone can contribute to its code and community. If you are curious what's new in the Thunderbird 91.0 branch, refer to this post.

Mozilla Thunderbird Banner

What's new in Thunderbird 91.1.2

  • CHANGED: Thunderbird will now warn if an S/MIME encrypted message includes BCC recipients
  • FIXED: Message Security popup did not display all recipients due a missing scrollbar
  • FIXED: Delivery Status Notifications were only shown for the first recipient
  • FIXED: Composing a message from a template with attachments failed due to a temporary file being removed
  • FIXED: Attachment sizes were no longer included on printed emails
  • FIXED: A message sent with multiple attachments sometimes only sent one
  • FIXED: Thunderbird sometimes attached the wrong messages when forwarding multiple messages by attachment
  • FIXED: Thunderbird did not re-prompt for an SMTP username if one was not provided
  • FIXED: Messages with BCC recipients that were held in the Outbox did not retain the BCC header when moved to the Sent folder
  • FIXED: Thunderbird displayed reminders for events that were cancelled or declined
  • FIXED: New Feed Account dialog did not honor dark mode

Download Thunderbird

Thunderbird users should eventually get the update automatically via the built-in update mechanism. To update it manually, select menu > Help > About Thunderbird to open the "About" dialog and initiate the update check. After that, the app should download and install the most recent version available.

Also, you can manually download the app from its official web site:

Download Thunderbird

The release notes are available here.


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Author: Sergey Tkachenko

Sergey Tkachenko is a software developer who started Winaero back in 2011. On this blog, Sergey is writing about everything connected to Microsoft, Windows and popular software. Follow him on Telegram, Twitter, and YouTube.

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