I’m not computer savvey
What could she hide on paper that would not be hidden on the electronic version?
The electronic version includes the metadata, which includes the Internet delivery addresses of all recipients including hidden ones (blind carbon copy).
Microsoft Exchange has the ability to bcc all email to an offsite escrow account. It is a standard feature of Exchange (IIRC). The escrow account is typically owned by a law firm to control legal discovery during litigation.
The electronic version of emails contains hidden ‘metadata’ that you don’t normally see.
It contains info about where the message was created and who it was sent to, so that it can be displayed properly on-screen.
All you usually see is the email text.