Keep a published rule when some invitation emails already went out, and only set Reply-To when the inviter address is a mailbox.

tests/unit/rulesPublishPostRoute.test.ts

@@ -202,6 +202,55 @@ describe("POST /api/rules", () => {
     });
   });
 
+  it("keeps the rule when a later invite send fails after one succeeded", async () => {
+    const created = {
+      id: "rule-partial",
+      title: "Published title",
+      summary: null,
+      createdAt: new Date("2026-01-02T00:00:00.000Z"),
+    };
+    transactionMock.mockImplementation(
+      async (
+        fn: (tx: {
+          publishedRule: { create: typeof vi.fn };
+          ruleStakeholder: { create: typeof vi.fn };
+        }) => Promise<unknown>,
+      ) => {
+        const tx = {
+          publishedRule: {
+            create: vi.fn().mockResolvedValue(created),
+          },
+          ruleStakeholder: {
+            create: vi.fn().mockResolvedValue({}),
+          },
+        };
+        return fn(tx);
+      },
+    );
+    sendInviteMock
+      .mockResolvedValueOnce(undefined)
+      .mockRejectedValueOnce(new Error("smtp down"));
+
+    const res = await POST(
+      new NextRequest("https://x.test/api/rules", {
+        method: "POST",
+        body: JSON.stringify({
+          title: "Published title",
+          summary: null,
+          document: {},
+          stakeholderEmails: ["first@example.com", "second@example.com"],
+        }),
+      }),
+      undefined,
+    );
+
+    expect(res.status).toBe(200);
+    expect(sendInviteMock).toHaveBeenCalledTimes(2);
+    expect(publishedRuleDeleteMock).not.toHaveBeenCalled();
+    const body = (await res.json()) as { rule: { id: string } };
+    expect(body.rule.id).toBe("rule-partial");
+  });
+
   it("creates an unlisted rule when there is no session", async () => {
     getSessionUserMock.mockResolvedValueOnce(null);
     publishedRuleCreateMock.mockResolvedValueOnce({