feat: add received_for to ReceivedEmail type

[lucasfcosta]

Adds the received_for field to the received email response type, matching the API.

---

Summary by cubic

Add the received_for field to the ReceivedEmail response type to mirror the API and expose forwarding recipients; update the async receiving test to assert this field.

^{Written for commit 08251e2. Summary will update on new commits.}

[cubic-dev-ai]

1 issue found across 2 files

Confidence score: 4/5

• In resend/emails/_received_email.py, received_for is required as List[str] while analogous fields are optional, so responses that omit it could fail model parsing for some non-forwarded emails and break email ingestion for those cases — align it to Optional[List[str]] (or add a default) before merging.

Prompt for AI agents (unresolved issues)

Check if these issues are valid — if so, understand the root cause of each and fix them. If appropriate, use sub-agents to investigate and fix each issue separately.


<file name="resend/emails/_received_email.py">

<violation number="1" location="resend/emails/_received_email.py:155">
P2: `received_for` is typed as `List[str]` (required) while similar optional list fields (`bcc`, `cc`, `reply_to`) are all `Optional[List[str]]`. If the API omits `received_for` for non-forwarded emails, this will cause a KeyError or type-checking issue.</violation>
</file>

<sub>Reply with feedback, questions, or to request a fix.

Re-trigger cubic</sub>

[cubic-dev-ai]

P2: received_for is typed as List[str] (required) while similar optional list fields (bcc, cc, reply_to) are all Optional[List[str]]. If the API omits received_for for non-forwarded emails, this will cause a KeyError or type-checking issue.

Prompt for AI agents

Check if this issue is valid — if so, understand the root cause and fix it. At resend/emails/_received_email.py, line 155:

<comment>`received_for` is typed as `List[str]` (required) while similar optional list fields (`bcc`, `cc`, `reply_to`) are all `Optional[List[str]]`. If the API omits `received_for` for non-forwarded emails, this will cause a KeyError or type-checking issue.</comment>

<file context>
@@ -152,6 +152,10 @@ class _ReceivedEmailDefaultAttrs(_ReceivedEmailFromParam, BaseResponse):
     """
     Reply-to addresses.
     """
+    received_for: List[str]
+    """
+    Addresses the email was received for (forwarding recipients).
</file context>