Take Note lets you add personal notes to emails and to label the notes with Outlook categories.
The add-in work on Outlook for Desktop, Outlook Web and Outlook on mobile devices.
The notes you add to an email are stored alongside your email but will never be visible to anyone else when replying or forwarding emails.
The add-in is very straightforward to use. Once the add-in is opened, simply type the text in the box provided and click "Add Note".
You can add multiple notes to an email or you can remove notes by cicking the "trash" icon.
If you would like TakeNote to automatically track which emails have notes against them and which do not then you can do this by renaming one of the color categories in Outlook to "TakeNote"
To rename an Outlook colour Category, just follow the instructions in the following link...