This is supposed to be MarkSubfolders "New" but it is NOT compatible with current version of Thunderbird 78. According to Thunderbird, this add-on is only good up to version 73.
Thunderbird 78 marks it as not compatible, and it's true--there is no option for marking subfolders as read under the right-click menu.
Have been waiting for this feature since previous version had become unavailable. This add-ons is very very useful just like before. Thank you so much!!! I'm using version 68.9.0 now.对这个附加组件，此用户曾发表过1个评价。
Have been looking to get "mark folder as read" back in my drop down menu for months. Have even tried creating a .css file from some instructions from another add on guy but that didn't work... Thought I'd give this a try, and OMG I have this option again! THANK YOU SO MUCH!! And I'm using 68.8.1
This extremely useful addon lives to fight another day in TB 68 if you are willing to do some moderate editing. Here's how. . .
1. Unzip the .xpi file (change extension to .zip to extract natively, or use 7-Zip or other extractor).
2. In extracted root folder, create "manifest.json" in a text editor and populate as follows (first bracket to last bracket):
"name": "MarkSubfolders New",
"description": "The menu 'Mark SubFolders Read' is added within the folder context-menu.",
"author": "H.Yasuda / M. Richter",
3. Save the file. Note that the JSON syntax is *very* finicky, and so much as one missing punctuation mark may cause the addon not to load. Copy and overwrite this addon's info over a manifest from a working TB 68 addon if you run into trouble. (Note also: this is a quick-and-dirty single language manifest; they can easily be localized per the TB Addon Developer website.)
4. Open "chrome.manifest" from the root folder in a text editor. Search and replace the following string (NOTE: -'s and +'s are for illustration only):
- overlay chrome://messenger/content/mailWindowOverlay.xul
+ overlay chrome://messenger/content/messenger.xul
5. Save file.
6. Open "markAllReadSubfolders.xul" in "../chrome/content/" subfolder in a text editor. Search and replace the following string:
7. Save file.
8. Open "markAllReadSubfolders.js" in "../chrome/content/" subfolder in a text editor. Search and replace the following string:
- gMarkSubfolders.folderFlagsVirtual = nsMsgFolderFlags.Virtual;
+ gMarkSubfolders.folderFlagsVirtual = Components.interfaces.nsMsgFolderFlags.Virtual;
9. Save file.
10. ZIP up addon, keeping complete folder structure. Change .zip extension to .xpi.
11. Install in TB 68.
Works perfectly on casual test, and error console stays quiet.
Can you pl. make it work for latest tb..which 61.*这个评论是针对附加组件的一个早期版本的（1.0.3）。
There is an easy fix for the addon to work on 60.*
1. Download the file marksubfolders_new-1.0.3-tb.xpi
2. Change the extension from .xpi to .zip
3. Unzip the file.
4. Edit the file install.rdf with notepad (or notepad++)
5. In line 17 change it from:
6. Save the file install.rdf
7. Zip again all the files (make sure that files are in the root of the zip and not in a folder)
8. Install it from file from Thunderbird addon manager.
Right now it's working in Thunderbird v. 60.3.2.
Worked until Thunderbird 60.3.0 . Is a fix in the works? This was one of the most convenient add-ons.这个评论是针对附加组件的一个早期版本的（1.0.3）。
This works well on 52.6.0 with accounts but not with Local Folders, is that something that can be easily fixed?这个评论是针对附加组件的一个早期版本的（1.0.3）。
MarkSubfolders add-on for Thunderbird works perfectly as advertised. Simple. Useful. Should be in "core" Thunderbird.
Old but works well with latest thunderbird version这个评论是针对附加组件的一个早期版本的（1.0.3）。
And it works with TB 45.2!这个评论是针对附加组件的一个早期版本的（1.0.3）。
You have people that offer buttons that they say mark all emails read, but only mark the emails in that folder read. This addon factually marks the mails in the folder ánd its subfolders read. This is added in the rightclick menu, right under the 'Mark Folder Read'. Very well done! (Thunderbird v45.0)这个评论是针对附加组件的一个早期版本的（1.0.3）。
Brilliant, thanks so much for making this work and acting as a replacement to the original application.这个评论是针对附加组件的一个早期版本的（1.0.3）。