There's a Thunderbird add-on called "Expression Search - NG" that provides advanced search options: - Add-on: https://addons.thunderbird.net/en-us/thunderbird/

There's a Thunderbird add-on called "Expression Search - NG" that provides advanced search options: - Add-on: https://addons.thunderbird.net/en-us/thunderbird/addon/expression-search-ng/ https://addons.thunderbird.net/en-us/thunderbird/addon/expre... - Source: https://github.com/opto/expression-search-NG https://github.com/opto/expression-search-NG It's a nice substitute for Outlook's Advanced Find feature, but without the GUI. (Despite the description, it is working on Thunderbird 91.)