I would also suggest a decent scanner. Store the scanned documents somewhere safe and backed up, and shred the paper copies.
Here is a scanner that I use;
When you say "save to YNAB", you mean save on the YNAB servers? I like how fast YNAB works, and would hate to see YNAB slow down as people are uploading receipts :-).
How about this as an alternative?
Scan your bills/receipts/statements;
https://www.amazon.com/gp/product/B017YUC984/
Then shred 'em;
First of all, buy a good scanner. I mean a really good one that is fast, scans both sides, and in color. I suggest:
https://www.amazon.com/gp/product/B017YUC984/
Scan all that shit, put all those files in a folder somewhere, and never ever open that folder.
Now shred it all. I suggest:
https://www.amazon.com/gp/product/B000WB397I/
When I wrote my last alimony check, I put (on the check) simply "Atlas Shrugged". I try not to think about it. I try not to get angry. Living well is indeed the best revenge.