email-amazon/DMS/docker-data/roundcube/plugins/email_config/config/config.inc.php

<?php
// TLS-Verifikation intern deaktivieren (Roundcube → DMS im Docker-Netz)
$config['imap_conn_options'] = [
    'ssl' => [
        'verify_peer'       => false,
        'verify_peer_name'  => false,
    ],
];
$config['smtp_conn_options'] = [
    'ssl' => [
        'verify_peer'       => false,
        'verify_peer_name'  => false,
    ],
];