diff --git a/src/app/api/admin/notifications/test/__tests__/route.test.ts b/src/app/api/admin/notifications/test/__tests__/route.test.ts
index 259a35461..796464b39 100644
--- a/src/app/api/admin/notifications/test/__tests__/route.test.ts
+++ b/src/app/api/admin/notifications/test/__tests__/route.test.ts
@@ -347,6 +347,7 @@ describe("POST /api/admin/notifications/test — a failure keeps its cause (#947
       upstreamStatus: 400,
     });
     expect(body.data.results[0].error).toContain("HTTP 400");
+    expect(body.data.results[0].error).not.toContain("hl-test");
   });
 
   it("tests the webhook channel rather than calling it unknown", async () => {
@@ -372,8 +373,9 @@ describe("POST /api/admin/notifications/test — a failure keeps its cause (#947
       success: false,
       errorCode: "upstream_rejected",
       upstreamStatus: 400,
-      upstreamBody: "priority must be an integer",
     });
+    // The relay body belongs to the settings card, not the admin toast.
+    expect(body.data.results[0].upstreamBody).toBeUndefined();
   });
 
   it("tests the email channel and forwards the SMTP code", async () => {
diff --git a/src/app/api/admin/notifications/test/route.ts b/src/app/api/admin/notifications/test/route.ts
index 0bf282198..4c71a805e 100644
--- a/src/app/api/admin/notifications/test/route.ts
+++ b/src/app/api/admin/notifications/test/route.ts
@@ -72,11 +72,12 @@ async function ensureTelegramChannel(userId: string): Promise<boolean> {
   return true;
 }
 
+/** The admin toast renders `errorCode` and the status; the relay body stays on the settings card. */
 type TestResult = {
   channel: string;
   success: boolean;
   error?: string;
-} & TestFailureDetail;
+} & Omit<TestFailureDetail, "upstreamBody">;
 
 /**
  * A failed HTTP or SMTP send, with the code, status and SMTP reply code the
@@ -87,21 +88,26 @@ function failedSend(
   channel: string,
   label: string,
   result: SendOutcome,
-  context?: string,
 ): TestResult {
-  const detail: TestFailureDetail = result.errorCode
-    ? { errorCode: result.errorCode }
+  const { errorCode, upstreamStatus, smtpCode } = result.errorCode
+    ? {
+        errorCode: result.errorCode,
+        upstreamStatus: undefined,
+        smtpCode: undefined,
+      }
     : testFailureDetail(result);
   const cause = result.errorCode
     ? `refused by the private-origin policy (${result.errorCode})`
-    : detail.errorCode
-      ? testFailureSentence(label, detail)
+    : errorCode
+      ? testFailureSentence(label, { errorCode, upstreamStatus, smtpCode })
       : (result.reason ?? "send failed");
   return {
     channel,
     success: false,
-    error: context ? `${cause} (${context})` : cause,
-    ...detail,
+    error: cause,
+    ...(errorCode ? { errorCode } : {}),
+    ...(upstreamStatus !== undefined ? { upstreamStatus } : {}),
+    ...(smtpCode !== undefined ? { smtpCode } : {}),
   };
 }
 
@@ -205,14 +211,8 @@ export const POST = apiHandler(async () => {
           const ntfyResult = await sendViaNtfy(config, payload);
           success = ntfyResult.ok;
           if (!success) {
-            results.push(
-              failedSend(
-                "NTFY",
-                "The ntfy server",
-                ntfyResult,
-                `topic: ${config.topic}`,
-              ),
-            );
+            // The topic is not echoed: on a public server it is the secret.
+            results.push(failedSend("NTFY", "The ntfy server", ntfyResult));
             continue;
           }
           break;
diff --git a/src/components/admin/__tests__/notification-test-failures.test.ts b/src/components/admin/__tests__/notification-test-failures.test.ts
new file mode 100644
index 000000000..b2fd9f403
--- /dev/null
+++ b/src/components/admin/__tests__/notification-test-failures.test.ts
@@ -0,0 +1,76 @@
+/**
+ * The admin notification test toast names each failing channel's cause
+ * (review L5): the code the route sends is translated and the status is
+ * shown, so the per-channel fields in the response have a reader.
+ */
+import { readFileSync } from "node:fs";
+import { join } from "node:path";
+import { describe, expect, it } from "vitest";
+
+import { describeChannelTestFailures } from "../notification-test-failures";
+
+const MESSAGES: Record<string, string> = {
+  "settings.testConnection.errors.upstream_rejected":
+    "The other end refused the message",
+  "settings.testConnection.errors.credentials_rejected": "Credentials rejected",
+  "admin.notificationTestFailed": "Failed to send test notification",
+};
+const t = (key: string) => MESSAGES[key] ?? key;
+
+describe("describeChannelTestFailures", () => {
+  it("lists only failing channels, with the translated cause and the status", () => {
+    expect(
+      describeChannelTestFailures(
+        [
+          { channel: "APNS", success: true },
+          {
+            channel: "WEBHOOK",
+            success: false,
+            error: "The webhook answered HTTP 400.",
+            errorCode: "upstream_rejected",
+            upstreamStatus: 400,
+          },
+          {
+            channel: "EMAIL",
+            success: false,
+            error: "The mail server rejected the credentials (SMTP 535).",
+            errorCode: "credentials_rejected",
+            smtpCode: 535,
+          },
+        ],
+        t,
+      ),
+    ).toEqual([
+      "Webhook: The other end refused the message (HTTP 400)",
+      "Email: Credentials rejected (SMTP 535)",
+    ]);
+  });
+
+  it("falls back to the route's sentence when there is no known code", () => {
+    expect(
+      describeChannelTestFailures(
+        [
+          {
+            channel: "NTFY",
+            success: false,
+            error: "SYSTEM_ALERT disabled in settings",
+          },
+          { channel: "MYSTERY", success: false, errorCode: "unlisted" },
+        ],
+        t,
+      ),
+    ).toEqual([
+      "ntfy: SYSTEM_ALERT disabled in settings",
+      "MYSTERY: Failed to send test notification",
+    ]);
+  });
+
+  it("is what the admin toast renders", () => {
+    const src = readFileSync(
+      join(process.cwd(), "src/components/admin/reminders-section.tsx"),
+      "utf8",
+    );
+    expect(src).toMatch(/describeChannelTestFailures\(data\?\.results/);
+    expect(src).toMatch(/description:/);
+  });
+});
diff --git a/src/components/admin/notification-test-failures.ts b/src/components/admin/notification-test-failures.ts
new file mode 100644
index 000000000..caf578b50
--- /dev/null
+++ b/src/components/admin/notification-test-failures.ts
@@ -0,0 +1,46 @@
+import {
+  CHANNEL_TYPE_LABELS,
+  type ChannelType,
+} from "@/lib/notifications/types";
+
+/** One channel's row in the admin notification test response. */
+export interface ChannelTestResult {
+  channel: string;
+  success: boolean;
+  error?: string;
+  errorCode?: string;
+  upstreamStatus?: number;
+  smtpCode?: number;
+}
+
+/**
+ * One line per failing channel for the admin test toast: the channel name,
+ * the cause in the admin's language (the same `settings.testConnection.errors`
+ * vocabulary the settings cards use), and the HTTP status or SMTP reply code.
+ * A row without a known code falls back to the route's own sentence.
+ */
+export function describeChannelTestFailures(
+  results: ReadonlyArray<ChannelTestResult>,
+  t: (key: string) => string,
+): string[] {
+  return results
+    .filter((r) => !r.success)
+    .map((r) => {
+      const label = CHANNEL_TYPE_LABELS[r.channel as ChannelType] ?? r.channel;
+      const key = r.errorCode
+        ? `settings.testConnection.errors.${r.errorCode}`
+        : null;
+      const translated = key ? t(key) : null;
+      const cause =
+        translated && translated !== key
+          ? translated
+          : (r.error ?? t("admin.notificationTestFailed"));
+      const code =
+        typeof r.upstreamStatus === "number"
+          ? ` (HTTP ${r.upstreamStatus})`
+          : typeof r.smtpCode === "number"
+            ? ` (SMTP ${r.smtpCode})`
+            : "";
+      return `${label}: ${cause}${code}`;
+    });
+}
diff --git a/src/components/admin/reminders-section.tsx b/src/components/admin/reminders-section.tsx
index ff4f28818..2a6d892d3 100644
--- a/src/components/admin/reminders-section.tsx
+++ b/src/components/admin/reminders-section.tsx
@@ -22,6 +22,10 @@ import { useTranslations } from "@/lib/i18n/context";
 import { queryKeys } from "@/lib/query-keys";
 import { useAdminSettings, useUpdateSettings } from "./_shared";
 import { apiGet, apiPost } from "@/lib/api/api-fetch";
+import {
+  describeChannelTestFailures,
+  type ChannelTestResult,
+} from "./notification-test-failures";
 
 interface NotificationHealth {
   windowHours: number;
@@ -132,19 +136,23 @@ export function RemindersSection() {
       return apiPost<
         | {
             message?: string;
-            results?: Array<{
-              channel: string;
-              success: boolean;
-              error?: string;
-            }>;
+            results?: ChannelTestResult[];
           }
         | undefined
       >("/api/admin/notifications/test");
     },
     onSuccess: (data) => {
-      const hasFailures = data?.results?.some((r) => !r.success);
-      if (hasFailures) {
-        toast.error(data?.message ?? t("admin.notificationTestFailed"));
+      const failures = describeChannelTestFailures(data?.results ?? [], t);
+      if (failures.length > 0) {
+        toast.error(data?.message ?? t("admin.notificationTestFailed"), {
+          description: (
+            <ul className="space-y-0.5">
+              {failures.map((line) => (
+                <li key={line}>{line}</li>
+              ))}
+            </ul>
+          ),
+        });
       } else {
         toast.success(data?.message ?? t("admin.notificationTestSuccess"));
       }