White space (plain old spaces), lots of them can be used to obscure something, e.g. push it outside the viewing area. This could be malicious or just poor use by the sender.
Presumably you have the Pro version as I don't believe this option is available to the Home version. I doubt that it would be repairable so it would then according to your actions, repair, if fails, delete, then the email is history/gone/is no more.
If this was an inbound email that was being scanned it is scanned outside the email folders, so a deletion would simply discard the email and it wouldn't end up in the deleted emails folder, etc.