Mail shows in Notes client, but when accessed in LotusScript the document has no items

I have a seriously weird issue. I have a mail which needs to be copied to another database. The mail contains attachments which are in the DAOS store. However, the DAOS store is long gone, so if I try to copy the mail by hand, I get an error "the object store database is disabled". I've had multiple mails like this and I wrote a script in LotusScript to copy all items which I could copy. Basically, if I remove the $File item, I can copy the rest.

However, now I have some mails left, which in the LotusScript debugger show no Notes items as part of the document object. That obviously means that there's no $File item to remove either. How is it possible that a mail is visible in the Notes client, you can see all fields in the properties box, yet when opened through LotusScript has no items whatsoever in the notesdocument object? Can anyone think of a possible explanation?

Are those documents encrypted? I think they will have a $Encrypt field (or something similarly obvious) but you won't see the other normal fields.