Block emails for all Gravity Forms (Eric Jones spam)

mu-block-emails-gf-all.php

function wpc_block_emails_on_all_forms($result, $value, $form, $field) {
    // Check if this is an e-mail field
    if ($field->type === 'email') {
        
        // List of e-mails to block
        $blocked_emails = ['[email protected]', '[email protected]'];

        // Standardize email format to avoid variations
        if (in_array(strtolower(trim($value)), $blocked_emails)) {
            $result['is_valid'] = false;
            $result['message'] = __('This e-mail address is incorrect. Please use another one.', 'wpchannel');
        }
    }

    return $result;
}
add_filter('gform_field_validation', 'wpc_block_emails_on_all_forms', 10, 4);