Log into Smartermail as the domain administrator

Click "Manage" for the domain

Create a new user (calendar, for example)

Login to the new user's webmail

Go to Settings > Sharing

Create a new Shared Resource

Add permissions

Once these steps have been completed, follow these steps below:

Login as a different user on that same domain

Go to Settings > Sharing > Mapped resources

Choose calendar and click "Attach"

Name the shared calendar

Go to Calendar Icon

Go to Calendar Drop Down Box - Click the shared calendar you wish to receive

Once the appropriate calendar is checked, or enabled, you'll then want to select Actions > Add to Outlook  (when you are filling in the info for Outlook, make sure you select the correct shared calendar from the drop down box)

Once you click Ok - it will prompt Outlook to open, and you can go to the calendar icon and see the shared calendar items appear.