In newer versions of Outlook for Mac, the KU single sign-on login portal will come up immediately upon opening Outlook. Sign in there with your new password to fix the email in that app.
For the older version of Outlook's UI, Outlook on the Mac may not prompt you to enter a new password, but it will show an icon next to your KU account that looks a bit like a sideways lightning bolt. You'll also see the status in the lower right as "Not Connected to: primaryEmail@ku.edu."
Click the indicator next to your KU account. This will pull up the KU single sign-on window, where you can enter your online ID and your new password.