There have been several requests for a spell check feature. Here is a spell check that you can download and use while posting messages on an MSN Group site.
Click on the link above and follow the directions given. There are 6 choices to chose from, I used the CNET Download.
After you have followed the download, you should be able to locate your Spell Check by clicking on "Tools" at the top of your browser and looking for ieSpell.
When you write a message and want to spell check, right click right above the "Use Plain Text editor" (do not check the box) above the message space and you will see the spelling tools- click on "check spelling"