downloading error

Whenever I open a file in email it automatically gets saved. I noted I have upwards of 8000 documents/files saved, thus making it impossible to find any necessary saved documents. In attempting to remove some of these unwanted files, I opened EXIT and clicked on "undo" only to have my MAC begin downloading every one of these files onto my desktop. SHutting the computer down does not stop the process; using "command Q" does not either. I can open two of the browsers, though the process is very very slow and the small rotating color wheel keeps rotating on my desktop. Is there anyone who could assist me? thanks

>force quit will always stop a program that is stubborn.