S&T IT staff is currently transitioning the email domain for Google Groups from mst.edu to grp.umsystem.edu. You should begin using groupname-grp@grp.umsystem.edu to send email 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 in Outlook on the Web.