If sending emails, talk of IE, firefox, chrome, opera etc may well be redundant. I used to use Outlook Express for email, but when they gave up supporting my hotmail accounts and their alternative offering of Windows Live failed to work properly, I shifted to Thunderbird. This needed a workaround back then, but the new versions are good - it sits there and does its job like it should.
For a browser, I use IE8 for shopping/financial stuff because it works solidly and competently and I am used to it, for browsing I have Chrome, because it works well at the level I need. I ditched firebox because of its habit of not only everlastingly wanted to update itself, but always wanted to brag about it, telling me how wonderful it was. That, and buying anything through it was a pain, very few vendors having software that worked with it.