Thunderbird 78.7.0 is a security and bug fix update (for the most part)

Martin Brinkmann
Jan 27, 2021
Email, Thunderbird

The email client Thunderbird 78.7.0 has been released on January 26, 2020. The new version of Thunderbird fixes security issues, improves the extensions system, and fixes several bugs on top of that.

The new version is already available and will be downloaded and in stalled automatically on many systems. Thunderbird users may select Help > About Thunderbird  (press the Alt-key if the menubar is not displayed) to display the currently installed version and to run a manual check for updates.

Thunderbird 78.7.0 is a security update. The security advisory page lists a total of six vulnerabilities that were fixed in the new version. The highest severity rating of vulnerabilities fixed in the update is high, the second-highest after critical.

As far as new features are concerned, there are four, and all four extend the APIs that extension developers have at their disposal to create Thunderbird extensions.

  • Extension API: Compose API now supports editing messages and templates as new messages
  • Extension API: composeHtml is now exposed in MailIdentity
  • Extension API: windows.update and windows.create now support titlePreface
  • Extension API: new Accounts API functions: accounts.getDefault() and accounts.getDefaultIdentity(accountId)

Extension APIs received several fixes and changes next to that>

  • Extension API: body and plainTextBody are now used as compose mode selectors in setComposeDetails and begin* functions in Compose API
  • Extension API: browserAction buttons were not restored after restart if they were moved outside the default toolbar
  • Extension API: browser.compose.beginNew could not override identity plaintext setting
  • Extension API: browser.compose.beginForward was ignoring ComposeDetails
  • Extension API: browser.compose.setComposeDetails did not properly handle Windows-style line endings

The development team fixed several theme related issues in the new release as well. The double border displayed around the task description field in the Tasks tab is removed in this release. Thunderbird's dark mode received three fixes as well; they fix a black text on black background issue in the folder properties dialog, and that the recipients were not visible when running Windows 10's high contrast dark theme. Lastly, the quickfilter bar buttons disappeared when hovering on them on Windows 10 systems with the high contrast black theme enabled.

Thunderbird's OpenPGP implementation has received several fixes in the release, including a verification issue caused by inline signed messages containing leading whitespace.

The last fix corrects an account manager issue. It occurred when a user deleted the last account in Thunderbird, as the default account would not get cleared in the process so that it still pointed to the account that no longer existed.

The release notes list a single known issue affecting users on Mac OS X. According to it, Thunderbird may perform sluggish on Mac OS Big Sur devices.

Now You: have you installed the new Thunderbird? What is your impression of the release?

Thunderbird 78.7.0 is a security and bug fix update (for the most part)
Article Name
Thunderbird 78.7.0 is a security and bug fix update (for the most part)
The email client Thunderbird 78.7.0 has been released on January 26, 2020. The new version of Thunderbird fixes security issues, improves the extensions system, and fixes several bugs on top of that.
Ghacks Technology News

Tutorials & Tips

Previous Post: «
Next Post: «


  1. Jonns said on January 27, 2021 at 9:57 pm

    Just a heads up to those who hoped the next update would fix the problems introduced in 78.6.1 with regard to recurring tasks and other calendar related anomalies: Nope.

    So, like me, if your calendar is an essential part of your Thunderbird experience and you need it to keep working properly, 78.7.0 is not your friend. Stick with 78.6.0 for now.

    1. P. Mergey said on January 29, 2021 at 2:00 pm

      At this time, I have to sadly agree with the comment above: furthermore, even reverting to a previous version (such as 78.5.1) doesn’t seem to fix the issue using a profile backup.

  2. Anonymous said on January 27, 2021 at 8:13 pm

    Now that Thunderbird has gone the snooping-for-profit Firefox way, we’d better be cautious with updates. I wonder when ghacks links will cause user bans from Thunderbird forums too, if they don’t already.

    1. owl said on January 28, 2021 at 2:44 pm


      Your claim is unclear. What is the problem, and what is the objective basis for it?
      What is the relationship between “ghacks links” and “Thunderbird forums”?
      Your comment seems to be grammatically incorrect, and it’s unclear what you want to sue.
      Please pay attention to the grammar and repost so that anyone can understand it.

  3. Franck said on January 27, 2021 at 5:07 pm

    Great news! Thank you for sharing!

  4. Derek Clements said on January 27, 2021 at 1:25 pm

    Have not installed it as yet – and perhaps never will, I’m currently running an ancient version which I do not send from – I’m in the process of finding an alternative. This is because it another configuration headache for the same reason that Firefox is a configuration nightmare; and that is mainly due to the fact that both teams have not consolidated and made available, detailed documentation of every “about:config” setting. I’ve been prepared to work through this in the past with Firefox, but my patience is drying up with the protracted process. This means that I may drop Firefox. I’m already investigating alternatives to Thunderbird, mainly Claws Mail and Emacs-Gnus(my preference if I can digest the documentation).
    Frankly, I don’t understand why an email client needs to be built from a web browser.

    1. Iron Heart said on January 27, 2021 at 11:57 pm

      @Derek Clements

      Check out Interlink:

      It’s a fork of Thunderbird 52, but regularly updated. Since it intends to stick with the codebase, its about:config is not subject to constant changes / the introduction of new settings.

      1. Derek Clements said on January 28, 2021 at 2:38 pm

        @Iron Heart:
        I shall investigate your suggestion and analyse. Always appreciate your tips, pointers and references – thank you.

Leave a Reply

Check the box to consent to your data being stored in line with the guidelines set out in our privacy policy

We love comments and welcome thoughtful and civilized discussion. Rudeness and personal attacks will not be tolerated. Please stay on-topic.
Please note that your comment may not appear immediately after you post it.