I use a mix of google email labels, apps script, spreadsheet & drive folder to download every email (older than 15 days, so that I have enough time to delete it

I use a mix of google email labels, apps script, spreadsheet & drive folder to download every email (older than 15 days, so that I have enough time to delete it) as .eml files in Google drive folder, which by turn downloads it to my local disk. The spreadsheet keeps log of each msg in a thread. Labels marks the downloaded emails. Apps script run on a trigger & does the heavy lifting of actually downloading the .eml.