default_option.php

См. документацию.

<?php
$subscribe_default_option = [
    'allow_anonymous' => 'Y',
    'show_auth_links' => 'Y',
    'subscribe_section' => '#SITE_DIR#about/',
    'posting_interval' => '20',
    'default_from' => '',
    'default_to' => '',
    'posting_charset' => 'Windows-1251,ISO-8859-1,UTF-8',
    'allow_8bit_chars' => 'N',
    'attach_images' => 'N',
    'subscribe_confirm_period' => '60',
    'subscribe_auto_method' => 'agent',
    'subscribe_max_emails_per_hit' => '5',
    'subscribe_template_method' => 'agent',
    'subscribe_template_interval' => '60',
    'max_bcc_count' => '0',
    'mail_additional_parameters' => '',
    'max_file_size' => '0',
    'max_files_size' => '0',
];