Thunderbird 78.6.0 is out: here is what is new

Martin Brinkmann
Dec 15, 2020
Updated • Dec 15, 2020
Email, Thunderbird

Thunderbird 78.6.0 has been released today. The new version of the email client is available for all supported operating systems -- Windows, Mac OS, and Linux -- as a direct update from within the client and a standalone download.

Thunderbird 78.6.0 is a security update that includes new features, changes, and a lot of fixes. Users may select Help > About Thunderbird to run a manual check for updates from within the clients (note that the update may not be available right away and that it may take a few hours before Thunderbird will pick it up).

Thunderbird 78.6.0

The functionality of MailExtensions, add-ons that Thunderbird supports, has been extended in this release. The function is now supported and developers may also use the menus API in messages being composed.

Additionally, there are two API changes: first, that the allowScriptsToClose argument is honored in windows.create API functions, and second, that accountld will reflect the account the message belongs to and not what is stored in message headers.

The remaining non-security changes are all bug fixes, and there are quite a lot of them.

  • OpenPGP: lots of fixes on this front, including fixes for importing keys on Mac OS (that failed), verification of clear signed UTF-8 text, for using decrypt and open/save as functionality with encrypted attachments, and discovery of online keys via the key manager on Linux. Engineers fixed another OpenPGP issue that showed the wrong key after importing a secret key in the properties, and improved inline PGP parsing.
  • Address Book: Fixed that the address book view did not update after chaning the name format, and that some columns did not display data (even when data was available).
  • Calendar: Fixed that two "home" calendars were displayed on new profiles, that ICS files could not be imporated in CalDAV calendards, and improved the Dark Theme on Linux.
  • MailExtensions: Fixed that HTTP refresh in browser content did not work, and that messageDisplayScripts failed to run in the main window.

Thunderbird 78.6.0 includes two visual improvements next to all that. Mail notification popups will display using a dark theme if dark theme is active, and several areas (folder icon, message list and contact side bar) have received visual improvements.

Thunderbird's development team lists  a single known issue that is affecting Mac OS Big Sur users: According to the release notes, Thunderbird may perform sluggish on devices running this version of Mac OS.

Thunderbird 78.6.0 includes eight security fixes. One of the eight security issues received the highest severity rating of critical, four a rating of high (second highest), one of moderate, and two of low.

Now You: Anything you would like to see in Thunderbird? Have you updated yet?

Thunderbird 78.6.0 is out: here is what is new
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Thunderbird 78.6.0 is out: here is what is new
Thunderbird 78.6.0 has been released today; our overview provides you with information on what is new and has changed in the open source email client.
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  1. JMGG said on January 19, 2012 at 8:25 am

    You said that Outlook isn’t your main email client, so which is your main one?

    1. BalaC said on January 19, 2012 at 9:42 am

      I think its thunderbird

    2. Martin Brinkmann said on January 19, 2012 at 10:15 am

      It is Mozilla Thunderbird.

  2. Salaam said on September 24, 2012 at 9:52 pm

    Awesome! This actually solved my problem… what a stupid bug.

  3. Claud said on December 19, 2012 at 2:08 am

    If this is the same bug that I’ve encountered, there may be another fix: (1) hover over open Outlook item in Taskbar, cursor up to hover over Outlook window item, and right-click; (2) this should give you Restore / Move / Size / Minimize / Maximize — choose Move or Size; (3) use your cursor keys, going arbitrarily N/S/E/W, to try to move or size the Outlook window back into view. Basically, the app behaves as though it were open in a 0x0 window, or at a location that’s offscreen, and this will frequently work to resize and/or move the window. Don’t forget to close while resized/moved, so that Outlook remembers the size/position for next time.

    1. Lynda said on February 12, 2013 at 3:37 pm

      THANK YOU Claude!!! I could get the main window to launch but could not get any other message window to show on the desktop. You are my hero!!!!

    2. Chad said on November 20, 2018 at 4:24 pm

      Solved my issue! 6 years later and this is still problem…

    3. Ivan X said on January 21, 2021 at 4:50 pm

      Fantastic. Thank you. Size did the trick.

  4. Andrew said on October 26, 2013 at 7:06 am

    This solved my Outlook problem, too. Thank you. :)

  5. Charles said on December 7, 2013 at 7:23 pm

    Thank you so much, this started happening to me today and was causing big problems. You are a life saver, I hope I can help you in some way some day.

  6. garth said on November 7, 2014 at 7:13 pm

    You are a god – thank you!

  7. Faisal said on February 9, 2015 at 10:09 am

    thanks a lot…. work like charm.. :-)

  8. Simon said on March 24, 2015 at 11:36 pm

    Yah…thanks Claude. I’ve been having the same problem and tried all the suggestions…your solution was the answer. It had resized itself to a 0/0 box. Cheers

  9. Olu said on April 14, 2015 at 1:35 pm

    Excellent post. This had me baffled even trying to accurately describe the problem. This fixed it for me.
    Thank you

  10. Coenig said on July 23, 2015 at 7:36 am

    Thanks a lot for the article. Don’t know why it happenend, don’t know how it got fixed, but it was really annoying and now it works :-)

  11. Fali said on January 20, 2016 at 4:19 pm

    Thanks a lot. I was facing this issue from past 3 week. I tried everything but no resolution. The issue was happening intermittently and mainly when I was changing the display of screen ( as i use 2 monitors). The only option i had was to do system restore. But thanks to you.

    1. MIki said on January 10, 2019 at 11:54 am

      I’ve been tried to sole this problem for 12hours. Your comment about changing the display of screen helped me a lot!! Thanks!!

  12. Christina said on January 20, 2016 at 6:14 pm

    Thank you…don’t know why this happened but your instructions helped me fix it. Running Windows 10 and office pro 2007

  13. Oz said on July 22, 2016 at 3:20 pm

    Great tip! Thanks!

  14. Tracy said on September 1, 2016 at 4:48 pm

    Worked for me, too – thank you!!!

  15. shawn said on September 9, 2016 at 10:25 am

    It’s Worked for me, too
    thank you very much!

  16. Jari said on October 31, 2016 at 11:53 am

    I had a similar issue with Outlook 2013 on Windows 10 and this helped me to fix it. Thank you very much!

  17. Michel H said on November 30, 2016 at 11:08 pm

    Thank you so much. Solved!
    Considering you published this in 2012, incredible not been debugged by Microsoft.
    Thank you again. M

  18. Ziad Bitar said on January 9, 2017 at 2:00 am

    This problem was faced by only one user logging to TS 2008 r2 using outlook 2010.The issue was resolved.


  19. Anonymous said on February 15, 2017 at 5:24 pm

    Great tip. Thank you!!!! If it helps, I had to use the Control Key and the arrow keys at the same time to bring my window back into view. Worked like a charm.

  20. Rochelle said on March 6, 2017 at 11:59 am

    Thank you, this worked !!!!

  21. anom1234 said on May 20, 2018 at 11:20 pm

    Man, you are a fucking god. Thanks a lot, what an annoying bug!!

  22. JC said on October 12, 2020 at 2:14 pm

    Awesome, this post solved the issue. Many thanks!

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