Change the default sorting order in Thunderbird

Solution 1:

Open the Config Editor from the following menu options:

Preferences > General > Config Editor

You might also find it at:

Tools > Options > Advanced > General > Config Editor

Or if you are using an older version of Thunderbird:

Preferences > Advanced > General > Config Editor

Type mailnews.default in the Filter bar to bring up a small list of preferences to configure. It will display similar to below:

Preference Name                      Status       Type        Value
mailnews.default_news_sort_order:    default      integer     x
mailnews.default_news_sort_type:     default      integer     y
mailnews.default_sort_order:         default      integer     x
mailnews.default_sort_type:          default      integer     y

In the above, replace the x and y of the value by double-clicking the name of the preference and replacing it with one of the following values as required:

x (see https://developer.mozilla.org/en/nsMsgViewSortOrder)

1 = Ascending
2 = Descending

y (see https://developer.mozilla.org/en/nsMsgViewSortType)

17 = None
18 = Date
19 = Subject
20 = Author
21 = ID (Order Received)
22 = Thread
23 = Priority
24 = Status
25 = Size
26 = Flagged
27 = Unread
28 = Recipient
29 = Location
30 = Label
31 = Junk Status
32 = Attachments
33 = Account
34 = Custom
35 = Received

So if you wanted to sort all mail by Thread, Descending (newest at top), the preferences in the config editor will look like this:

mailnews.default_sort_order:    default     integer      2
mailnews.default_sort_type:     default     integer     22

There are also default_(news_)view_flags settings (for mail and news), which allow to turn on the "Threaded" flag:

view_flags -- the second group of values can be added to one of the first group to combine effects, with several limitations:
  Unthreaded       0
  Threaded         1
  Grouped         64  [mail only (?)]

  ShowIgnored      8  [news only]
  ShowUnreadOnly  16
  ShowExpanded    32  [doesn't seem to work]
ShowUnreadOnly will check the View|Threads|Unread menu; this will cause only
unread items to be seen, but doesn't force a threaded view.

(See also: https://bugzil.la/86845#c74)

Solution 2:

A simpler solution : Using the Thunderbird SortPref module.

enter image description here

Provides settings to control which order messages are sorted initially and by which field as well as whether to display in threaded mode. Please note this data ends up stored in each folder, so changing control values only affect new folders or those with a rebuilt index. The mechanics are described in https://bugzilla.mozilla.org/show_bug.cgi?id=86845 - this extension merely adds gloss to somebody else's actual code.

Solution 3:

This is just an extension to the accepted answer, since unfortunately such types of edits are not accepted.

The only problem that the answer doesn't address is getting this applied everywhere, not only to the folders that were first opened after the change. Thanks Danation for providing the idea.

Close Thunderbird
Locate your Thunderbird profile folder (mine was under /home/my_user_name/.thunderbird)
cd to that folder
Run find . -name '*.msf' -print0 | xargs -0 rm
Open Thunderbird