RamblingRoss
The blog of Ross Fruen, a .NET consultant Thunderbird running slowly on Windows 10
Documenting a Thunderbird fix found a few months after Windows 10 was first launched.
As that time Thunderbird was performing very poorly with frequent lock-ups.
After much googling it appeared the Windows Search indexer was at fault, by turning off the option Tools | Options | Advanced | General | System Integration | Allow Windows Search all the problems went away.!