There should be a Notes folder tucked away among your other mail folders. It won't show up in Mail on the iPad, but should show up on the Macbook Air. The notes go there. Chances are that there is a preference somewhere that decides if they also show up in the Inbox on the computer. That's how the stock OS X Mail app works.
If the folder is missing, make sure you've got Note syncing turned on in your email account on the iPad. Make a note in Notes, and see where it shows up in Outlook. Put the old notes back there.
Because I don't have Outlook, and I don't know what kind of email account you are using that's about as detailed as I can make it. Sorry.