EmailConstraint.php

<?php

namespace Drupal\Core\Validation\Plugin\Validation\Constraint;

use Symfony\Component\Validator\Constraints\Email;

/**
 * Count constraint.
 *
 * Overrides the symfony constraint to use the strict setting.
 *
 * @Constraint(
 *   id = "Email",
 *   label = @Translation("Email", context = "Validation")
 * )
 */
class EmailConstraint extends Email {
    
    /**
     * {@inheritdoc}
     */
    public function __construct($options = []) {
        $options += [
            'mode' => 'strict',
        ];
        parent::__construct($options);
    }
    
    /**
     * {@inheritdoc}
     */
    public function validatedBy() {
        return '\\Symfony\\Component\\Validator\\Constraints\\EmailValidator';
    }

}