Why are there two folders, "junk" and "spam"?

All your help verbiage seems to treat them as one, but the program doesn't We have emails cycle from spam to inbox to spam, and the only way to deal with them is to delete them The inbox decides they are spam (how?) and does it repeatedly regardless of the various attempts to move them back to the inbox. There are no "not spam" action commands. Please get rid of the spam folder (classify everything as junk) or give us some management tools to direct emails to their proper location.