And is this from a web mail email account, or using email software like Outlook, Thunderbird, etc.
If it is just one file, tell us more about this file.
When I try to send an attachment I get this message: file could not be sent check to see if the file is open in another application. It is definately not open. I reset explorer 8, I uninstalled aol & reinstalled, tried changing security to a lower level. Nothing work. I'm running window xp.