Managing email sucks...so many you have to keep as they are not quite relevant now, but you will need them when they are.
I have manually set up folders that I know will hold whatever mail is important, I leave the rest in my inbox and periodically purge it as I approach my 50mb quota on the Exchange server.
Keep in mind Outlook folders are also limited to about 2GB each, they used to self destruct when you surpassed the limit, but the latest service packs fixed that.
2GB of mail though is insane, the people I have had to help with that have had email back 2 years and most of it unread with huge attachments.