I have saved a large number of cd on an extermal drive via my laptop. I have now moved my external drive to my desk to but I tunes does not find all the CD i have saved on the external drive
Depending on which email client software you use
the files should be in 'your home folder' library, esp.
if you use Mail application.... ~/Library/Mail
Since you don't specify what mail application,
that would most be associated with the file.
I notice there are some items to the right of your post
where it says "more like this' so that may be worth a
look to see if similar issues were answered. Also, the
Help viewer in your system is a searchable database.
Seems that google also brings up fair information, too.
Do you have a complete bootable clone of your entire
Mac system on an externally enclosed hard disk drive?
Good luck & happy computing!