Guide

1. Right-click the table and select 'Design View'.

2. Click on the field where emails will be entered.

3. In the 'Field Properties' pane, locate the 'Validation Rule' property and click on the ellipsis icon.

4. Enter the rule and click 'OK'.

5. In the 'Validation Text' property, enter a user-friendly error message.

6. Save the changes to apply the rule by clicking the save icon.