Alertmanager debugging

Run in Console

alertmanager --config-file=/usr/local/etc/alertmanager/alertmanager.yml --log.level=debug --storage.path=/var/db/alertmanager --web.external-url="http://x.x.x.x:9093"

Check the Logs

Look for failed notifications like these

# /var/log/alertmanager.log

level=error ts=2022-02-20T15:39:13.058Z caller=dispatch.go:354 component=dispatcher msg="Notify for alerts failed" num_alerts=2 err="smtp-local/email[0]: notify retry cancelled after 5 attempts: establish connection to server: dial tcp [::1]:25 /io timeout"