docs: config.yml.example - document NS8 relay auto-detection, simplify smtp section

config/config.yml.example

@@ -1,49 +1,84 @@
 # ns8-backup-monitor configuration
 
-# SMTP settings for notification emails
+# ---------------------------------------------------------------------------
+# SMTP settings
+# ---------------------------------------------------------------------------
+# By default (use_ns8_relay: true), ns8-backup-monitor automatically reads
+# the SMTP relay configured in NethServer 8 from the cluster Redis state
+# (key: cluster/mail_settings). This is the same relay used by NS8 itself
+# for system notifications, so no manual SMTP setup is needed in most cases.
+#
+# The fallback chain is:
+#   1. NS8 Redis (cluster/mail_settings)  <-- default, preferred
+#   2. smtp section below
+#   3. localhost:25 unauthenticated
+#
+# To disable auto-detection and use the settings below, set:
+#   use_ns8_relay: false
 smtp:
+  use_ns8_relay: true   # set to false to force manual SMTP config below
+
+  # Manual SMTP config (used only if use_ns8_relay: false or NS8 relay not found)
   host: localhost
-  port: 25
+  port: 587
   use_tls: false
-  use_starttls: false
+  use_starttls: true
   username: ""
   password: ""
 
+# ---------------------------------------------------------------------------
 # Notification recipients
+# ---------------------------------------------------------------------------
 mail:
+  # Sender address.
+  # If use_ns8_relay: true, the 'from' is read from NS8 Redis (mail_from field).
+  # You can override it here if needed.
   from: "ns8-backup-monitor@yourdomain.com"
+
+  # List of recipients - REQUIRED, always set this
   to:
     - "admin@yourdomain.com"
+
   subject_prefix: "[NS8 Backup]"
 
+# ---------------------------------------------------------------------------
 # Webhook receiver settings
+# ---------------------------------------------------------------------------
 receiver:
   host: "127.0.0.1"
   port: 9099
 
-# Timing: how many seconds to wait after alert before checking
+# ---------------------------------------------------------------------------
-# (allows all modules to finish writing their status)
+# Timing
+# ---------------------------------------------------------------------------
 correlator:
+  # Seconds to wait after alert before checking Redis status.
+  # Allows all modules to finish writing their status.
   wait_seconds: 30
   # Time window (seconds) to consider a backup "recent" after alert
   recent_window: 3600
 
+# ---------------------------------------------------------------------------
 # Redis connection (NS8 cluster state)
+# ---------------------------------------------------------------------------
 redis:
   socket: "/var/lib/nethserver/cluster/state/redis.sock"
   # Alternatively use host/port if not using unix socket
   # host: "127.0.0.1"
   # port: 6379
 
-# Repository check: commands to run to verify backup destination
+# ---------------------------------------------------------------------------
-# These are run as root and should return exit code 0 on success
+# Repository check
+# ---------------------------------------------------------------------------
 repo_check:
-  # Maximum seconds to wait for repo check
+  # Maximum seconds to wait for each repo check
   timeout: 60
-  # Additional restic flags if needed
+  # Additional restic flags if needed (e.g. '--cacert /path/to/ca.crt')
   restic_flags: ""
 
+# ---------------------------------------------------------------------------
 # Logging
+# ---------------------------------------------------------------------------
 logging:
   level: INFO
   file: "/var/log/ns8-backup-monitor.log"