{
    "log_file": "stderr",
    "log_level": "debug",
    "backend_config": {
        "save_workers_size": 1,
        "log_received_mails": false
    },
    "servers": [{
        "is_enabled": true,
        "max_size": 1000000,
        "listen_interface": "0.0.0.0:25",
        "timeout": 30,
        "max_clients": 3
    }]
}