What is the keyboard shortcut for Keep Text Only in Outlook?
I figured it out. It isn't Ctrl+T, it is Ctrl, T (as in press and release Ctrl, then press T).
So, the pattern to paste as text only is: Ctrl+V, Ctrl, T.
Another option is Alt+H+V+T (i.e., keeping Alt pressed until after you press T).
There is an option with a small number of keystrokes, which does not involve an intermediate paste-with-format:
Ctrl+Alt+V, Unformatted text
Taken from an excellent summary of shortcuts.