Mozilla Thunderbird 52.9.0 released

The Thunderbird team has released a new version of the open source cross-platform email client. Thunderbird 52.9.0 is a security update first and foremost which makes it a recommended update for all users of the email client.
The new version of Thunderbird fixes the so-called EFAIL security issue completely. EFAIL was discovered earlier this year by security researchers. It allows attackers to gain access to OpenPGP or S/Mime encrypted messages by managing to get hold of encrypted messages, for instance by network snooping, modifying the emails, and sending them to the target.
The Thunderbird development team fixed the issue partially in Thunderbird 52.8.0 which it released in May 2018.
The release of Thunderbird 52.9.0 fixes the issue completely by removing "some HTML crafted to carry out" an EFAIL attack, and optionally "not decrypting subordinate message parts that otherwise might reveal decrypted content to the attacker".
The optional feature is not enabled by default. You can enable it in the following way in the Thunderbird client:
- Select Tools > Options from the menu bar. If you don't see the menu bar, tap on the Alt-key to display it.
- Go to Advanced > General.
- Click on Config Editor.
- Search for mailnews.p7m_subparts_external.
- Double-click on the preference.
- Close the window.
A value of true means that the feature is enabled, a value of false (default) that it is disabled.
Thunderbird 52.9.0 fixes 13 security vulnerabilities; four vulnerabilities have received the highest impact rating of critical.
The new version of Thunderbird includes two non-security changes next to that. It fixes issues "when forwarding messages inline when using "simple" HTML View. Thunderbird supports three view types: original HTML, simple HTML, and plain text.
The difference between Original and Simple HTML is that Thunderbird blocks some elements, e.g. remote content automatically whereas you get an option to enable it with Original HTML view.
The final change of Thunderbird 52.9.0 is a change in how IMAP folders are handled by the client. Starting with this version, Thunderbird will prompt users to compact IMAP folders even if the account is online.
Existing Thunderbird users can run a manual check for updates to use Thunderbird's built-in updating functionality. Just select Help > About Thunderbird to do so.
The new email client version is also available as a direct download on the official Thunderbird project website.


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!