This user obviously uses some dubious spam protect method that auto-replies to each incoming message
The message you sent requires that you verify that you
are a real live human being and not a spam source.
To complete this verification, simply reply to this message and leave
the subject line intact.
Now every time something is posted in a topic that the user is subscribed to, the user (Clark@harkins2.com) receives a notification, and each time this auto-reply is sent back to the forum.
I don't want to discuss this very dubious method of spam prevention, but how we can prevent such feedback to be posted in the forum. Is there a way to filter such things before they are posted in the forum topics?