Whenever you download a file from the Web with your browser, using an FTP client or get files as e-mail attachments the software may store additional information about the origin of the files. This information may contain the source URL of the file. In the case of an e-mail attachment it can contain the e-mail address of the sender and the subject.
With AVT WhereFrom you can view this information and remove it if needed.
MacOSX 10.6 or above
WhereFrom is currently only available on the Mac App Store.