It is not posssible to get ALL Hotmail accounts pushed to a BB. Some were grandfathered in, but Microsoft has required most to upgrade to Hotmail plus.
How to add / delete email addresses - BlackBerryFAQ
If you have followed the directions to add an email account to your carrier's BIS, and simply entered your username and password for Hotmail, and it doesn't work, then yours does not. I know having an account with them for seven years sounds like it should, but that is a discussion you need to take up with MS...
Good luck, and also, welcome to the Forums.