Editor control with edit option for WinForms

Question

I am creating an Outlook AddIn, where clicking on AddIn button the mailBody of the particular mail will be stored in the control.

Also i should be able to edit the contents of the control.

I tried using following:

 

https://yarte.codeplex.com/

or

http://www.codeproject.com/Articles/15559/A-Windows-Forms-based-text-editor-with-HTML-output

But it supports plain text editing doesn't support editing for rich text.

I am really stuck on this

Any help !!!