plain text mails in alertmanager

[Evelyn Pereira Souza]

Hi

This is my current alertmanager config:

- name: 'mail_example.org'
email_configs:
- to: 'te...@example.org'
headers:
subject: "Example: {{ .GroupLabels.alertname }} is {{ .Status }}"
send_resolved: true

It's sending out HTML formated mails.

I wish to send out plain text mails. I saw several issues and a PR, but
I can't figure out howto enable it.

best regards
Evelyn