See my answer there - this isn't a bug. MFCMAPI just reports what was set. File names in Windows are NOT case sensitive. EVER. And different MAPI clients will provide different data as inputs.
You're clearly fascinated by these details- but why? What does it break for you that sometimes an 8.3 name is lowercase and sometimes it's upper case? Why does it matter that some clients provide a long name for PR_ATTACH_FILENAME? What's the impact?
You're clearly fascinated by these details- but why? What does it break for you that sometimes an 8.3 name is lowercase and sometimes it's upper case? Why does it matter that some clients provide a long name for PR_ATTACH_FILENAME? What's the impact?