Dr Byte:

First thanks for the fast reply.

Admin->Configuration->Email Options->Email Admin Format? .... TEXT vs HTML
It was set to HTML, however I just changed it to TEXT and tried again.
Same results:
email to administrator displays plain text only
email to a customer email address displays as html

I presume the correct setting for Admin->Configuration->Email Options->Email Admin Format is html so will reset it back to html.

The text editor used is HTLMarea

Ron