Outlook was the best tool I found for organizing. One thing that's a little bizarre about gmail is that it doesn't use folders. Instead, it uses labels. Its organizing system takes a while to get used to but like everything else, given time, it works itself out.

If nothing else, it's free to investigate. I can't remember if I tried porting my Yahoo mail over to gmail, because I already had most of it in Outlook from the time I had a paid account. Since losing mail is one of my pet peeves, I never minded having a lot of redundant backup systems. I actually have multiple gmail accounts and forward them all to my primary account so I don't have to check each one individually.