Custom validation email and error message in registration

You can use custom code to validate and check if the user's email address upon registration already exists or is already in use and display your custom error message.

Go to wp-admin > Ultimate Member > Forms > Edit Registration Form find the "Email-Address" field and click the Edit button.

Set the Validate option to the Custom Validation in the field settings and input user_email_details in the Custom Action option. Then click on the Update button to save changes.

Then use the custom code below. You can add this code snippet to the functions.php file in the active theme directory.

The code above will also check if the user has inputted the correct email address or made typographical errors upon registration. This way, users will know if they provided an invalid email address or check if they made any errors.