Pm2-health send to many emails when a process died

Question

I am using pm2-health to trigger when a process was managed by pm2 died. But every time a process died, pm2-health send 11 emails about exception threw and 11 more emails about process has stopped. And when I manual stopped the process, pm2 health send 2 emails about process has stopped.How can I configure pm2-health to send only one email each time. Thank you!

Here is my module_conf.json file:

{
    "pm2-health": {
        "smtp": {
            "host": "smtp.gmail.com",
            "port": 587,
            "user": "sender@gmail.com",
            "password": "pass",
            "disabled": false
        },
        "mailTo": "receiver@gmail.com",
        "replyTo": "",
        "batchPeriodM": 1,
        "batchMaxMessages": 20,
        "events": [
            "exit"
        ],
        "exceptions": true,
        "messages": true,
        "messageExcludeExps": [],
        "metric": {},
        "metricIntervalS": 60,
        "aliveTimeoutS": 300,
        "addLogs": true,
        "appsExcluded": [],
        "snapshot": {
            "url": "",
            "token": "",
            "auth": {
                "user": "",
                "password": ""
            },
            "disabled": false
        }
    },
    "module-db-v2": {
        "pm2-health": {}
    }
}