Hello bradbjc

You can select multiple emails to delete at a time,

Please login to MSN click on Mail and More

Just above the first email you will see a line (which has From,  Subject, Received) right click on it.

Select Display Column

Click on Restore Defaults

For more information please go to the below link.

https://support.microsoft.com/en-us/contactus/msn/explorer-tech-services/

Thanks

MSN Support Team.