Well unfortunately my email archives are at home so I cant verify this.
However, it is not unusual for a sale confirmation to come from one domain name (i.e. combatmission2.com) and a shipping notice to come from another domain (battlefront.com).
Battlefront may have created their online web store with the domain name combatmission2.com and it is sending out the preorder confirmations automatically.
This email appears to be from a distribution center at http://www.endicia.com.
I know this because the email has a link to this website (with my confirmation number added to the end of the link) and it takes me to a confirmation message.
This notice is also listed at the bottom of the page:
Important Note. This package status web-page was generated by Endicia Internet Postage at the sender's request. If you have questions about the package delivery, please contact the sender or the U.S. Postal Service directly. Endicia will not be able to answer any delivery questions, as we do not have any information other than what is shown on this page.