# `Mailglass.Stream`
[🔗](https://github.com/szTheory/mailglass/blob/v0.1.0/lib/mailglass/stream.ex#L1)

Stream policy seam (SEND-01 stage 3, D-25).

At v0.1 this is a no-op that returns `:ok` for every valid stream
(valid streams are enforced at schema level via `Ecto.Enum` on
`Mailglass.Outbound.Delivery.stream`). Emits a single telemetry
event for observability.

v0.5 DELIV-02 swaps this implementation in place; callers do not
change. The v0.5 impl will enforce:

- `:transactional` stream: no tracking injection allowed
- `:bulk` stream: RFC 8058 List-Unsubscribe header auto-injected
- Per-stream provider routing via per-tenant adapter resolver (DELIV-07)

Why a no-op seam at v0.1 rather than "omit the stage": the preflight
pipeline (Plan 05) is stable across versions. Adding stream_policy
later would be a breaking change to the pipeline order; shipping a
no-op now locks the contract.

# `policy_check`
*since 0.1.0* 

```elixir
@spec policy_check(Mailglass.Message.t()) :: :ok
```

Checks stream policy for the given message. Returns `:ok` at v0.1 for all streams.

Pattern-matches on `%Mailglass.Message{}` only — passing a raw map raises `FunctionClauseError`.
Emits `[:mailglass, :outbound, :stream_policy, :stop]` telemetry on every call.

v0.5 DELIV-02 will swap this implementation; callers do not change.

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*Consult [api-reference.md](api-reference.md) for complete listing*