Enable Maildir storage in Thunderbird #

UPDATE: See Convert mbox-based Local Folders to Maildir in Thunderbird 102.

Maildir offers a number of advantages over mbox. Thunderbird 38 offers experimental support for Maildir; read the warnings and caveats before enabling.

Steps:

Thunderbird > Preferences > Advanced > Config Editor...
Search for mail.serverDefaultStoreContractID
Change the default @mozilla.org/msgstore/berkeleystore;1 value to @mozilla.org/msgstore/maildirstore;1
Restart Thunderbird

Notes:

The drop down box for "Message Store Type for new accounts" in the Advanced preference pane remains greyed out (in spite of these instructions to the contrary) but does accurately report the current value, either the default "One large file (mbox)" or "File per message (maildir)".
The change only applies to newly-created accounts, not existing ones.
If you want to create a fake test account, click File > Offline > Work Offline before setting it up, otherwise Thunderbird will not allow an unverified account to be created.
It may be safest to create a new profile for experimenting with Maildir. Access the Profile Manager like so:
- Linux: $ thunderbird -profilemanager
- OS X: $ /Applications/Thunderbird.app/Contents/MacOS/thunderbird-bin -ProfileManager
- Windows: C:\>thunderbird.exe -ProfileManager

***

A few notes on the "death" of Thunderbird:

So, That’s It For Thunderbird (2012) "Mozilla is not 'stopping' Thunderbird development, it has just decided that: 'continued innovation on Thunderbird is not the best use of our resources given our ambitious organizational goals.' And it’s pulling people off the project. But it’s not stopping? Right."
Mozilla scraps Thunderbird development - email client 'not a priority' anymore (2012) "Thunderbird's 20 million users will in future only get security updates from Mozilla, apparently because people are switching to other messaging technologies and aren't bothered with further email innovation"
Future of Thunderbird (last updated Dec 2014) "The Thunderbird project is not dead. It is still a Mozilla project even though new development and bug fixing is now done by the community. Mozilla continues to provide the infrastructure (both the Mozilla add-ons web site and the servers used to build, test and distribute new versions), and add stability/security fixes ... One quick way to verify for yourself that Thunderbird development is still active is to take a look at The Rumbling Edge. It tracks developments in Thunderbird builds. You could also browse the Thunderbird status meetings minutes to see what people say they are working on."

/misc | Oct 15, 2015