I use Firefox because if IE ever gets corrupted, you must reinstall the OS. I've seen that happen. That's the main reason Microsoft went through the monopoly lawsuit back in the late 90's. Well, that and MS 'strongly encouraged' Intel to not have a java code lookup table incorporated into their processors.
Outlook express is another MS program I will not use due to security concerns. It has too many links to the system kernel and low level operations. In its defense, I believe if you know what you are doing, those security holes can be patched.
To me it's analogous to eating a brownie then getting sick. You just don't have much of a taste for that any more. Having been burned by IE and seen what problems it can cause, I am not comfortable using it for anything other than Windows updates.
Regards,
Malta