confused, I'm not sure what your point is, maybe I'm being thick again.
My point is that if/when you back up it is best to do it on a different drive. This is because the original is on the system disc, and if the back up is on a seperate data disc, there are two chances of avoiding corruption as against one.
This can be done by copying the folder you made from the desktop to the other drive, or by changing where the files are archived to, (change address in Mail Folder.) If a seperate off system back up is needed this can be made from either.
This won't save all the settings, but those are replicable; the data might not be.
And as to space, even 3000 long emails won't take that much unless they are image rich or something.
Hope this is clearer, and it wasn't really addressing the core problem, so no big deal, just a suggestion to refine things.