Cool idea. Looks like there's a thunderbird extension for this but it's woefully out of date and hasn't been updated since 2011. Maybe you can revive it? https

Cool idea. Looks like there's a thunderbird extension for this but it's woefully out of date and hasn't been updated since 2011. Maybe you can revive it? https://addons.thunderbird.net/en-US/thunderbird/addon/gather-the-senders/ https://addons.thunderbird.net/en-US/thunderbird/addon/gathe...