Dex, it's like anything, if you procrastinate long enought, the task becomes to large.
As mentioned above, always keep one account for professional purposes only. This not only solves the problem of friends sending you inappropriate images that you open in board meeting, but an informal account also allows you to distribute your address online or otherwise, (these days you need an email to access/ enter many websites).
With hotmail, it's important to save important messages to folders. That's the easiest way to archive mail, ie, tax, rent, insurance, etc.
The trick is, with your professional account, always send important mail to their appropriate folder.
Best advice I can give is, open each mail every day, 'delete' anything useless instantly, then archive immediately.
If you still find yourself with 10 gig of mail you want to keep, open an new account.
