Thunderbird 78.4.0 email client with fixes and extensions capabilities

Thunderbird 78.4.0 is now available. The new version of the email client includes several important fixes and extensions improvements.
Thunderbird 78.4.0 is available for all supported operating systems (Windows, Linux and Mac OS). Existing installations should pick up the new version automatically and install it.
Users may run a manual check for updates by selecting Help > About Thunderbird. If the main menu is not displayed, press the Alt-key to display it. The page that opens displays the currently installed version as well.
Thunderbird 78.4.0 can also be downloaded directly from the project website. The "all" downloads page is the best choice in this regard as it downloads the full installer to the system.
Thunderbird 78.4.0
MailExtensions, the extensions system that Thunderbird supports, have new capabilities starting in this new version of the email client. MailExtensions work like WebExtensions in browsers such as Firefox or Chrome.
The new capabilities introduces the browser.tabs.sendMessage API and messageDisplayScripts API that extension developers may use to extend functionality of existing extensions or create new extensions that utilize the new APIs.
Additional MailExtensions related changes add support for creating messages with attachments to the compose.begin function, and extend the messageDisplay API by adding support for selecting multiple messages.
Another change introduced in Thunderbird 78.4.0 affects Yahoo and AOL mail users. The password authentication is migrated to OAuth2 in the release. It is unclear if this requires an active action of the user or if the migration happens in the background. Migration happens in the background according to Sören Hentzschel.
Thunderbird 78.4.0 comes with several fixes, including security fixes. The team fixed three security issues in the new email client versions that have all received a severity rating of high, the second highest rating after critical. You can check out the listing here.
As far as bug fixes are concerned:
- Fixed a freeze in Thunderbird when the global search index ran updates.
- Fixed multiple unnamed issues of the handling of self-signed SSL certificates.
- Various keyboard navigation and color-related theme fixes.
- Default folder icon button was not accessible via the keyboard.
- Recipient addresses in compose would expand to fill out all available space.
- Emojis in compose windows caused unexpected behavior.
- MailExtensions fix for updating attachments with onBeforeSend.addListener().
The installation went through without any issues on two systems that are used daily. You can check out the entire release notes here.
Now You: Do you use Thunderbird?


You said that Outlook isn’t your main email client, so which is your main one?
I think its thunderbird
It is Mozilla Thunderbird.
Awesome! This actually solved my problem… what a stupid bug.
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.
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!!!!
Solved my issue! 6 years later and this is still problem…
Fantastic. Thank you. Size did the trick.
This solved my Outlook problem, too. Thank you. :)
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.
You are a god – thank you!
thanks a lot…. work like charm.. :-)
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
Excellent post. This had me baffled even trying to accurately describe the problem. This fixed it for me.
Thank you
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 :-)
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.
I’ve been tried to sole this problem for 12hours. Your comment about changing the display of screen helped me a lot!! Thanks!!
Thank you…don’t know why this happened but your instructions helped me fix it. Running Windows 10 and office pro 2007
Great tip! Thanks!
Worked for me, too – thank you!!!
It’s Worked for me, too
thank you very much!
I had a similar issue with Outlook 2013 on Windows 10 and this helped me to fix it. Thank you very much!
Thank you so much. Solved!
Considering you published this in 2012, incredible not been debugged by Microsoft.
Thank you again. M
This problem was faced by only one user logging to TS 2008 r2 using outlook 2010.The issue was resolved.
Thanks.
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.
Thank you, this worked !!!!
Man, you are a fucking god. Thanks a lot, what an annoying bug!!
Awesome, this post solved the issue. Many thanks!