HTML email with random!

Newly installed instance of RT 4.4.1. Email is being sent with random "! " (bang space) inserted in the body of the messages - most frequently right in the middle of a word or a URL where is most disruptive to the reader. When I look at the plain text version in the same email there are no problems. The ticket doesn’t have the problem. It is only the email HTML version that has this corruption. Anyone have hints for me?