I had to add a POP3 account to a user who's outlook was already configured with an Exchange 2010 account. The POP3 account is from the same exchange server. The purpose of the POP3 account is to send out newsletters. The credentials provided for the POP3 account are the same as the user's exchange account. The email address for the POP3 account is configured not to receive email from the outside.
Now all email the user receives is automatically marked as read when it gets delivered. The user uses Outlook 2010.