Why does Thunderbird use so much memory? As far as a "browser" goes, it appears pretty barebones, yet it's showing some of the highest RAM usage on my device, while it's not even doing anything! Here's my use case: I have an install of Thunderbird that I use only for the calendar (don't ask why). I have no email accounts synced to it; I have everything related to email disabled or hidden that I possibly can. There is one CalDAV calendar that it displays (but I know the issue is NOT frequent background syncs, because if I change an event on my phone, I still have to click Thunderbird's "Synchronize" button for it to update from the server). With the minimal usage described above, Thunderbird has 3 processes visible in Windows Task Manager, using a total of 18% of my RAM pretty consistently. In comparison, I also have Brave Browser open to Gmail. Brave, with half a dozen extensions installed, heavy JS usage, and constant telemetry/pinging google servers, has 19 processes in Task Manager, but all together consistently uses ''under 14% of RAM''. '''Why in the world does Thunderbird use more memory just to sit idle with one calendar open than does a Chromium browser with constant traffic??'''