To fix issues adding or editing notes in Outlook, try using Ctrl+Shift+N for a new note, ensuring you are in the "Notes" folder (via Navigation Bar or Ctrl+5), or checking that your Outlook is updated to build 16.0.11126.20266+ for desktop fixes. If using the "New Outlook," notes are now found in the folder list of the folder pane

• Create New Note: Press Ctrl+Shift+N or select More Apps (three dots) on the navigation bar and choose Notes.
• Edit Existing Note: Open the Notes folder, double-click the note, make changes, and click the note icon to Save & Close.
• Fix Editing Issues (Desktop): If notes are uneditable, your Outlook may need an update (specifically for versions prior to April 2019) to fix an issue with internet headers.
• Web/New Outlook: Navigate to the Notes folder, select the note, and click to edit, or use the "OneNote feed" icon for Sticky Notes.
• Shared Mailboxes: If in a shared mailbox, ensure you are using a view that allows editing.