Outlook by default checks emails every 30 minutes. If you think this does not work for you, you can change the email check interval with the steps below:
Step 1: Click the "Send/Receive" tab from the ribbon;
Step 2: Click "Send/Receive Groups" button in the tab;
Step 3: Select "Define Send/Receive Groups" from the drop-down list;
Step 4: In the new window, check the box of "Schedule an automatic send/receive every 30 minutes", and change "30" to the number you want (e.g., "15");
Step 5: Click "Close" to close the window.
