Data validation is a powerful Excel feature that can be used to restrict what data can or should be entered in a cell. You can setup data validation to prevent users from entering invalid data.
In this post I am sharing with you a tip on how to setup data validation setup to restrict users from entering invalid email addresses by applying a formula based Data Validation rule.
In the example below, We can create a Data validation formula in Column D by choosing Custom as the validation criteria in the Data Validation settings.
This animation demonstrates how it should be done.