Ran a recovery program (Kroll Ontrack) on a Windows 7 PC and recovered many, many emails. Almost all of them open in my Windows 10 mail client (and Thunderbird), except for a handful from this March. They look like the image above, and even some are blank. These are not empty files, though, as they have file sizes ranging from a few KB to 16 MB. Incidentally, these are the most important emails. Is this a sign of a .eml being encrypted? Or is it something else? And all of the other emails have perfectly fine images, docs, PDFs, etc. Just these handful from March look like this.
I'm not asking how to decrypt these, I just want to know if a series of emails that look similar to this is a sign of them being encrypted in the first place.