IE6 service pack 1 contains a really cool feature for Outlook Express that nobody seems to be talking about much.
In IE6 there is an issue with webbugs, little snippets of code that allow spammers to track where and when you read their spams. These are used to validate email addresses as active and to return feedback to spammers on how many people actually saw their spam so they can charge the advertiser. Currently unless you firewall OE so it can only talk to your mail server you can't block webbugs, there is no off switch.
Anyway, in Service Pack 1 they have added a text only feature to OE. Go to Tools menu, then options, then the read tab and it's listed as "read all messages in plain text".
This is fantastic! Besides extracting only the text out of html emails it stops webbugs, scripts, and other email exploits. HIGHLY recommended by me to turn this thing on if you are concerned about security!