Using Grafana Template for Email Subject. Email Notifications are sent to recipients with no subject in some cases

Grafana Alerting
6

As I said - report only first X alerts in the subject. For example I report only first 5 alert via MS team:

{{ define "generic.msteams.alerts" }}
{{- $alerts := . -}}
{{ if gt (len $alerts) 5 }}
First 5 alerts only:
{{ $alerts = slice $alerts 0 5 }}{{- else -}}
{{ end -}}
  {{- range $alerts }}
    {{- template "generic.msteams.alert" . -}}
  {{- end -}}
{{- end -}}

Or disable grouping - then million failing instances = million alert emails (and not one email with million alertnames)