Wordpress/Contact Form 7: Block form submissions from @gmail.com addresses

functions.php

function cf7_check_email_field($result, $tags) {
    $wpcf = WPCF7_ContactForm::get_current();

    // Check if the current form ID is 9052
    if ($wpcf->id !== 9052) {
        return $result;
    }

    // Get the posted email data
    $submission = WPCF7_Submission::get_instance();
    $posted_data = $submission->get_posted_data();
    $email = $posted_data['your-email'];

    // Check if the email address is from Gmail
    if (preg_match('/@gmail\.com$/', $email)) {
        $result->invalidate($tags, __('We do not accept @gmail addresses.', 'text_domain'));
        return $result;
    }

    return $result;
}

// Hook the function to the wpcf7_validate_email and wpcf7_validate_email* filters
add_filter('wpcf7_validate_email', 'cf7_check_email_field', 20, 2);
add_filter('wpcf7_validate_email*', 'cf7_check_email_field', 20, 2);