The "empty outer body + message/rfc822 attachment" unwrap heuristic
(built for Outlook's blank-body forwards) was also matching Forward as
attachment sends, which intentionally use a blank body. Once unwrapped
for inline preview, the .eml attachment itself was filtered out of the
attachment list, so a sent forward-as-attachment message with a large
attached .eml appeared to have no attachments at all.
Aaron Guise
aad6bbd028