I have the same question I USED to have my mail set up where everything was combined (inbox, sent, junk ect.) but after a update awhile back it separated everything & now I'm left routing through multiple folder levels just to clear or delete junk mail which based on the rules I've built should have just gone to the trash. with seven different accounts the daily task is maddening and considering the number of queries regarding this same question I can't believe that apple is not aware of the problem. It's awful.