ngx_mail_core_create_srv_conf(ngx_conf_t *cf)
{
    ngx_mail_core_srv_conf_t  *cscf;

    cscf = ngx_pcalloc(cf->pool, sizeof(ngx_mail_core_srv_conf_t));
    if (cscf == NULL) {
        return NULL;
    }

    /*
     * set by ngx_pcalloc():
     *
     *     cscf->protocol = NULL;
     *     cscf->error_log = NULL;
     */

    cscf->timeout = NGX_CONF_UNSET_MSEC;
    cscf->resolver_timeout = NGX_CONF_UNSET_MSEC;

    cscf->max_errors = NGX_CONF_UNSET_UINT;

    cscf->resolver = NGX_CONF_UNSET_PTR;

    cscf->file_name = cf->conf_file->file.name.data;
    cscf->line = cf->conf_file->line;

    return cscf;
}
The software does not validate, or incorrectly validates, a certificate.