The e-mails are stored in C:\Users\<your username here>\AppData\Local\Microsoft\Windows Mail\
But if the edited attachment is not located there it would be in C:\Users\<your username here>\AppData\Local\Temp (provided it has not been automatically deleted).
Hope this helps,
I can't find where file attachments are in Microsoft Mail. I opened a file (Excel), edited it, and did a save (not save as). I haven't been able to find the file, and if I open the attachment in the mail, I get the original attachment. In addition, in XP if you did a Save AS, you would see the OLK9 folder. If you do a Save As in Vista / Microsoft Mail, it defaults to \my documents. Does anyone have any idea where these files are located? I've done system/hidden searches, and can't find anything.