How to archive question (not saving to a .pst)

[usmdesigner]

A friend of mine set up my outlook (2003) so I could "drag" emails down to a set of folders in my "all mail folders" list and it "archive" it. When placed under the folders I named, it doesn't use up the max memory (getting that warning "your memory is full&quot, yet anytime I want to view those emails, they are readily available to see. I tried looking on google to find it, but maybe I'm not searching correctly. Does anyone know how this is done or can link a tutorial on how it is done?