Tested on:
OpenSuSE 15.0 with Thunderbird 60.0 (email accounts only)
Windows 10 x64 with Thunderbird 60.2.1(32bit) (email accounts only)
macOS 10.13.3 with Thunderbird 60.2.1(64bit) (email accounts only)
NOT tested:
All other setups
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Warning:
Please be careful using this updated plugin. It can kill your Thunderbird account config.
Make a backup of your Thunderbird config dir.
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This extension for Thunderbird 60+ adds a "Manually sort folders" entry into the Tools menu. Use it to, hum, manually sort your accounts and folders (that was obvious, wasn't it?).
I sometimes put a development version online, but over the past eight years, I've only updated this addon twice, as it is very stable; so your best bet is to just stick with the publicly available version on AMO.