One might say that my relationship with various methods of receiving bills and receipts is "complicated".

And that's not counting the ones where you have to log into their site every month to download an encrypted file and copy the individual file's passcode. Nobody has time to securely store a file-by-file passcode. Either give it to me unencrypted or use a single passcode that applies to every file.

(This topic came to mind because of @clacke's discussion of storing his receipts in #DeltaChat (which AFAIK is just a chat-like interface atop e-mail ... so I guess all that would also be available in his inbox).