Reads SquatchMail's application configuration.

The host application configures SquatchMail like any other library:

config :squatch_mail,
  repo: MyApp.Repo,
  otp_app: :my_app,
  prefix: "squatch_mail",
  enabled: true,
  capture: [
    store_html: true,
    store_text: true,
    sample_rate: 1.0,
    max_queue: 10_000,
    max_concurrency: 50
  ],
  guard: [
    complaint_rate_pause: true,
    complaint_rate_threshold: 0.001,
    complaint_rate_window_days: 30,
    min_volume: 100,
    prune_interval_ms: :timer.hours(24)
  ]

Options

• :repo (required) - the Ecto.Repo SquatchMail uses to read and write its own tables. This is expected to be the host application's existing repo; SquatchMail keeps its tables isolated in their own Postgres schema (see :prefix).
• :otp_app - the OTP application configuring SquatchMail. Used by future installer/asset tasks to locate the host app's directories.
• :prefix - the Postgres schema all SquatchMail tables live in. Defaults to "squatch_mail".
• :enabled - whether SquatchMail's capture/ingestion machinery is active. Defaults to true. Useful for disabling SquatchMail in specific environments (e.g. test) without removing its configuration.
• :capture - options for the telemetry capture engine (SquatchMail.Capture), a keyword list:
  • :store_html - whether to persist the HTML body. Defaults to true. Set to false to keep engagement/status data while dropping potentially sensitive HTML content.
  • :store_text - whether to persist the plain-text body. Defaults to true, same rationale as :store_html.
  • :sample_rate - the fraction (0.0..1.0) of outgoing emails the capture engine persists. Defaults to 1.0 (capture every send). Lower this for very high-volume mailers where full capture would be too much write load; 1.0 and 0.0 are treated as exact (no random sampling overhead at the extremes).
  • :max_queue - the maximum number of captured emails the SquatchMail.Capture.Recorder will hold pending persistence before it starts dropping new captures (and emitting [:squatch_mail, :capture, :dropped]) rather than let the queue grow unbounded under a burst. Defaults to 10_000.
  • :max_concurrency - the maximum number of captures being persisted to the database at once. Distinct from :max_queue: :max_queue bounds how many captures can be waiting, while :max_concurrency bounds how many of those waiting captures are simultaneously checking out a connection from the host's Repo pool, so a burst can't itself exhaust that pool. Defaults to 50.
• :guard - options for SquatchMail.Guard, a keyword list:
  • :complaint_rate_pause - whether the complaint-rate circuit breaker is active at all. Defaults to true; set to false to disable it entirely (suppression checks still run).
  • :complaint_rate_threshold - the fraction (0.0..1.0) of sent emails, over the trailing :complaint_rate_window_days, that have been complained about before SquatchMail.Guard auto-pauses sending. Defaults to 0.001 (0.1%), matching SES's own account-suspension threshold.
  • :complaint_rate_window_days - the trailing window, in days, the complaint rate is computed over. Defaults to 30.
  • :min_volume - the minimum number of sent emails in the trailing window before the complaint-rate breaker can trip. Defaults to 100, so e.g. 1 complaint out of 5 sends doesn't falsely read as a 20% complaint rate.
  • :prune_interval_ms - retained for backwards compatibility; prefer :pruner's :interval below.
• :pruner - options for SquatchMail.Pruner, a keyword list:
  • :interval - how often, in milliseconds, the pruner calls SquatchMail.Tracker.prune/0. Defaults to 6 hours.
  • :enabled - whether the pruner runs at all. Defaults to true.