Grafana sends empty emails every minute

Hello Community,

I have Grafana 7.5.11 running and Prometheus. I have problems with empty emails which i receive every minute. I think it has something to do with the routing alerts, cause when i change to 5 minutes i receive those empty emails every 5 minutes. My alerts in the dashboard are running correctly.

Here is my routing rule:

receiver: 'mail_receiver'
group_wait: 30s
group_interval: 1m
repeat_interval: 4h
group_by: [cluster, alertname]

And here my email alert receiver:

to: ''
from: ''
headers:  { subject: "[ALERT] - [{{ .ExampleLabels.severity }}]  - {{ .ExampleAnnotations.summary }}"  }
html: '{{ template "email.example.html" . }}'
text: "This is an alert."

Can anyone help on this?

Is there anyone who can help???