why do need to use netscape communicator?!!
If you really think its the staples emails that freeze your computer, you can block domains in your hotmail account. So just block @staples.com emails from coming in. You can also check your hotmail using Outlook express if you want.
Personally, I don't think your problem lies with emails from staples. I think it may be rooted some where in your setup. but your know your situation better than I do.