The IT staff is currently transitioning the e-mail domain for Google Groups from mst.edu to grp.umsystem.edu. You should begin using groupname-grp@grp.umsystem.edu to send e-mail to any Google group. If you have a rule set up in Outlook to deliver incoming group messages to a specific folder, you should replace the groupname-grp@mst.edu address with groupname-grp@grp.umsystem.edu to continue having those messages delivered to the correct folder.
Visit Microsoft Support online for guidelines on creating and editing inbox rules in Outlook and Outlook on the Web.