Send E-Mail from alertmanager by using AWS SES as SMTP server

Alertmanager can be configured to send notifications to different targets, Slack, Email, PagerDuty etc.

Use the below steps to configure AWS SES as SMTP server to send E-Mails from alertmanager

• The from address should be already verified in AWS SES to send E-Mails from that address

• Check and confirm if you have secret named "alertmanager-main" in monitoring namespace

• Create a file called alertmanager.yaml with below contents, modify as needed

"global": 
  "resolve_timeout": "5m"
"receivers": 
- "name": "org-prometheus-notify"
  "email_configs":
  - "to": "ksundararajan@organization.com"
    "from": "noreply@organization.com"
    "smarthost": "email-smtp.us-east-1.amazonaws.com:587"
    # The catch here is aws access key and secret won't work here, we should create SMTP credentials from AWS Console
    "auth_username": "<SMTP_USERNAME>"
    "auth_password": "<SMTP_PASSWORD>"
    "require_tls": true
"route": 
  "group_by": 
  - "job"
  "group_interval": "5m"
  "group_wait": "30s"
  "receiver": "org-prometheus-notify"
  "repeat_interval": "12h"
  "routes": 
  - "match": 
      "alertname": "Watchdog"
    "receiver": "org-prometheus-notify"

• Create alertmanager-secret-k8s.yaml with below contents

apiVersion: v1
data:
  alertmanager.yaml: ALERTMANAGER_CONFIG
kind: Secret
metadata:
  name: alertmanager-main
  namespace: monitoring
type: Opaque

• Execute the below command to update the secret by using the contents in alertmanager.yaml

sed "s/ALERTMANAGER_CONFIG/$(cat alertmanager.yaml | base64 -w0)/g" alertmanager-secret-k8s.yaml | kubectl apply -f -

• Alertmanager pods will reload the configuration change by itself and should start sending E-Mails.