Outlook supports spell checking in tasks, contacts, email, posts but not in Notes. This is because Notes uses a much simpler rich text editor than the other times and has fewer features as result.
Since notes are for my reference only, I don't care about the spelling, but if you do, you can either compose the note in a new mail message or post form and paste it into the note or copy from the note and paste into a new message form to spell check then paste it back. That's a Ctrl+A, C, P, then spell check and repeat.
If you choose to compose it in another Outlook form (or even in Word), you can save a couple of keystrokes if you select the text and drag it to the Note icon (also works in reverse – select the text in a note and drag to a mail folder).
Yes, this works on more than just Notes. You can use this method to create new Outlook items from emailed messages or other items – drag the entire message from the Inbox to the Contacts or Calendar icon if you want it all in a note or select part of the message and drag. (This capability one of my all-time favorite Outlook features.
Published January 22, 2007. Last reviewed on June 15, 2011.