alerta.conf (alerta-mailer troubles...)

alerta.conf

[DEFAULT]
debug = True
endpoint = http://localhost:8080/api
key = {{ alerta_cli_api_key }}
output = json
sslverify = False
timezone = Europe/London

[alerta-mailer]
amqp_topic = notify
amqp_url = {{ db_type }}://{{ db_user }}:{{ db_passwd }}@{{ db_loc }}/kombu
config_file = /app/alerta.conf
dashboard_url = https://{{ domain }}
debug = True
email_type = text
endpoint = http://localhost:8080/api
key = {{ alerta_mailer_api_key }}
mail_from = {{ mail_from }}
mail_to = {{ mail_to }}
skip_mta = False
smtp_host = {{ smtp_host }}
smtp_password = {{ smtp_passwd }}
smtp_port = {{ smtp_port }}
smtp_starttls = True
smtp_username = {{ mail_from }}

Runner logs...

alerta@440297312f61:/$ env | grep -i smtp
SMTP_PASSWORD=...my smtp password...
alerta@440297312f61:/$ alerta-mailer
DEBUG:mailer:Looking for rules files in /app/alerta.rules.d
Authentication failed.
DEBUG:urllib3.connectionpool:Starting new HTTP connection (1): localhost:8080
Starting new HTTP connection (1): localhost:8080
DEBUG:urllib3.connectionpool:http://localhost:8080 "POST /api/heartbeat HTTP/1.1" 403 139
http://localhost:8080 "POST /api/heartbeat HTTP/1.1" 403 139