diff --git a/src/main/app-controller.ts b/src/main/app-controller.ts
index 4f75299..3481ec9 100644
--- a/src/main/app-controller.ts
+++ b/src/main/app-controller.ts
@@ -78,6 +78,8 @@ import { createOnlineBackup, downloadOnlineBackup, uploadOnlineBackup } from "./
 import { overlayLiveUsageCounters } from "./settings-live-overlay";
 import { getLegacyDesktopLogDirectory, migrateLogDirectories, prepareLogDirectory, resolveLogDirectory } from "./log-storage";
 import { normalizeStatisticsLedger, saveStatisticsLedger } from "./statistics-ledger";
+import { NotificationOutbox } from "./notification-outbox";
+import { sendNotification } from "./notify";
 
 function sanitizeSettingsPatch(partial: Partial<AppSettings>): Partial<AppSettings> {
   const entries = Object.entries(partial || {}).filter(([, value]) => value !== undefined);
@@ -118,6 +120,8 @@ export class AppController {
 
   private storagePaths = createStoragePaths(path.join(app.getPath("userData"), "runtime"));
 
+  private notificationOutbox: NotificationOutbox;
+
   private logDirectory = this.storagePaths.baseDir;
 
   private onStateHandler: ((snapshot: UiSnapshot) => void) | null = null;
@@ -150,9 +154,24 @@ export class AppController {
     }
     this.initializeLogStorage();
     resetHistoryForRetention(this.storagePaths, this.settings.historyRetentionMode);
-    const loadResult = loadSessionWithStatus(this.storagePaths);
-    const session = loadResult.session;
-    this.megaWebFallback = new MegaWebFallback(() => ({
+    const loadResult = loadSessionWithStatus(this.storagePaths);
+    const session = loadResult.session;
+    this.notificationOutbox = new NotificationOutbox({
+      filePath: this.storagePaths.notificationOutboxFile,
+      autoDrain: true,
+      send: (event) => sendNotification(this.settings.notifyUrl, {
+        title: event.payload.title,
+        message: event.payload.description || "",
+        mention: this.settings.notifyMention,
+        color: event.payload.color ?? (event.priority === "error" ? 0xe74c3c : 0x2ecc71),
+        fields: event.payload.fields,
+        timestamp: event.createdAt
+      })
+    });
+    void this.notificationOutbox.drain().catch((error) => {
+      logger.warn(`Notification-Outbox konnte nicht gestartet werden: ${String(error)}`);
+    });
+    this.megaWebFallback = new MegaWebFallback(() => ({
       login: this.settings.megaLogin,
       password: this.settings.megaPassword
     }));
@@ -1273,9 +1292,12 @@ export class AppController {
       clearInterval(this.runtimeStatsTimer);
       this.runtimeStatsTimer = null;
     }
-    stopDebugServer();
-    abortActiveUpdateDownload();
-    cancelPendingAsyncSaves();
+    stopDebugServer();
+    abortActiveUpdateDownload();
+    cancelPendingAsyncSaves();
+    void this.notificationOutbox.drainForShutdown().catch((error) => {
+      logger.warn(`Notification-Outbox konnte beim Beenden nicht geleert werden: ${String(error)}`);
+    });
     this.manager.prepareForShutdown();
     this.megaWebFallback.dispose();
     for (const fallback of this.realDebridWebFallbacks.values()) {
diff --git a/src/main/notification-outbox.ts b/src/main/notification-outbox.ts
new file mode 100644
index 0000000..9067da6
--- /dev/null
+++ b/src/main/notification-outbox.ts
@@ -0,0 +1,302 @@
+import fs from "node:fs";
+import fsp from "node:fs/promises";
+import path from "node:path";
+import type { DiscordEmbedFieldPayload } from "./notify";
+
+export type NotificationEventType =
+  | "package_completed"
+  | "package_partial"
+  | "package_failed"
+  | "run_completed"
+  | "run_stopped"
+  | "remaining_threshold_crossed"
+  | "download_stalled"
+  | "download_recovered";
+
+export type NotificationPriority = "success" | "error";
+
+export interface NotificationEventPayload {
+  title: string;
+  description?: string;
+  color?: number;
+  fields: DiscordEmbedFieldPayload[];
+}
+
+export interface NotificationEvent {
+  id: string;
+  type: NotificationEventType;
+  priority: NotificationPriority;
+  createdAt: number;
+  expiresAt: number;
+  attempts: number;
+  nextAttemptAt: number;
+  payload: NotificationEventPayload;
+}
+
+export interface NotificationOutboxStatus {
+  queued: number;
+  lastSuccessAt: number;
+  lastFailureAt: number;
+}
+
+export interface NotificationOutboxOptions {
+  filePath: string;
+  send: (event: NotificationEvent) => Promise<boolean>;
+  now?: () => number;
+  autoDrain?: boolean;
+}
+
+interface PersistedNotificationOutbox {
+  version: 1;
+  events: NotificationEvent[];
+  lastSuccessAt: number;
+  lastFailureAt: number;
+}
+
+const EVENT_TYPES = new Set<NotificationEventType>([
+  "package_completed",
+  "package_partial",
+  "package_failed",
+  "run_completed",
+  "run_stopped",
+  "remaining_threshold_crossed",
+  "download_stalled",
+  "download_recovered"
+]);
+const MAX_EVENTS = 250;
+const MAX_RETRY_DELAY_MS = 10 * 60 * 1000;
+const DEFAULT_SHUTDOWN_TIMEOUT_MS = 3000;
+
+function finiteInteger(value: unknown, fallback = 0): number {
+  const numeric = Number(value);
+  return Number.isFinite(numeric) ? Math.max(0, Math.floor(numeric)) : fallback;
+}
+
+function sanitizeEvent(value: unknown): NotificationEvent | null {
+  if (!value || typeof value !== "object" || Array.isArray(value)) {
+    return null;
+  }
+  const raw = value as Partial<NotificationEvent>;
+  const id = typeof raw.id === "string" ? raw.id.trim().slice(0, 256) : "";
+  const type = EVENT_TYPES.has(raw.type as NotificationEventType) ? raw.type as NotificationEventType : null;
+  const priority = raw.priority === "success" || raw.priority === "error" ? raw.priority : null;
+  const payload = raw.payload && typeof raw.payload === "object" && !Array.isArray(raw.payload)
+    ? raw.payload as NotificationEventPayload
+    : null;
+  const title = typeof payload?.title === "string" ? payload.title.slice(0, 4096) : "";
+  if (!id || !type || !priority || !payload || !title) {
+    return null;
+  }
+  const fields = Array.isArray(payload.fields)
+    ? payload.fields.slice(0, 25).flatMap((field) => {
+      if (!field || typeof field !== "object") {
+        return [];
+      }
+      const name = typeof field.name === "string" ? field.name.slice(0, 1024) : "";
+      const fieldValue = typeof field.value === "string" ? field.value.slice(0, 4096) : "";
+      return name && fieldValue ? [{ name, value: fieldValue, inline: Boolean(field.inline) }] : [];
+    })
+    : [];
+  const description = typeof payload.description === "string" ? payload.description.slice(0, 8192) : undefined;
+  const color = Number.isFinite(payload.color)
+    ? Math.max(0, Math.min(0xffffff, Math.floor(payload.color as number)))
+    : undefined;
+  return {
+    id,
+    type,
+    priority,
+    createdAt: finiteInteger(raw.createdAt),
+    expiresAt: finiteInteger(raw.expiresAt),
+    attempts: finiteInteger(raw.attempts),
+    nextAttemptAt: finiteInteger(raw.nextAttemptAt),
+    payload: {
+      title,
+      ...(description !== undefined ? { description } : {}),
+      ...(color !== undefined ? { color } : {}),
+      fields
+    }
+  };
+}
+
+function oldestIndex(events: NotificationEvent[], predicate: (event: NotificationEvent) => boolean): number {
+  let selected = -1;
+  for (let index = 0; index < events.length; index += 1) {
+    if (!predicate(events[index])) {
+      continue;
+    }
+    if (selected < 0 || events[index].createdAt < events[selected].createdAt) {
+      selected = index;
+    }
+  }
+  return selected;
+}
+
+function retryDelayMs(attempts: number): number {
+  return Math.min(MAX_RETRY_DELAY_MS, 1000 * (2 ** Math.min(9, Math.max(0, attempts - 1))));
+}
+
+export class NotificationOutbox {
+  private events: NotificationEvent[] = [];
+  private lastSuccessAt = 0;
+  private lastFailureAt = 0;
+  private operationChain: Promise<void> = Promise.resolve();
+  private readonly filePath: string;
+  private readonly sendEvent: (event: NotificationEvent) => Promise<boolean>;
+  private readonly clock: () => number;
+  private readonly autoDrain: boolean;
+  private retryTimer: NodeJS.Timeout | null = null;
+  private shutdownRequested = false;
+
+  public constructor(options: NotificationOutboxOptions) {
+    this.filePath = options.filePath;
+    this.sendEvent = options.send;
+    this.clock = options.now || Date.now;
+    this.autoDrain = Boolean(options.autoDrain);
+    this.load();
+  }
+
+  public async enqueue(event: NotificationEvent): Promise<void> {
+    await this.runExclusive(async () => {
+      const normalized = sanitizeEvent(event);
+      if (normalized && !this.events.some((queuedEvent) => queuedEvent.id === normalized.id)) {
+        this.events.push(normalized);
+      }
+      await this.persist(this.clock());
+    });
+    if (this.autoDrain) {
+      this.scheduleDrain(0);
+    }
+  }
+
+  public drain(now?: number): Promise<void> {
+    return this.runExclusive(async () => {
+      const drainAt = finiteInteger(now ?? this.clock());
+      this.enforceLimits(drainAt);
+      while (this.events.length > 0) {
+        const current = this.events[0];
+        if (current.nextAttemptAt > drainAt) {
+          break;
+        }
+        let sent = false;
+        try {
+          sent = await this.sendEvent(current);
+        } catch {
+          sent = false;
+        }
+        if (!sent) {
+          current.attempts += 1;
+          current.nextAttemptAt = drainAt + retryDelayMs(current.attempts);
+          this.lastFailureAt = drainAt;
+          await this.persist(drainAt);
+          if (this.autoDrain) {
+            this.scheduleDrain(Math.max(0, current.nextAttemptAt - this.clock()));
+          }
+          break;
+        }
+        this.events.shift();
+        this.lastSuccessAt = drainAt;
+        await this.persist(drainAt);
+      }
+      if (this.events.length === 0) {
+        this.clearRetryTimer();
+        await this.persist(drainAt);
+      }
+    });
+  }
+
+  public async drainForShutdown(timeoutMs = DEFAULT_SHUTDOWN_TIMEOUT_MS): Promise<void> {
+    this.shutdownRequested = true;
+    this.clearRetryTimer();
+    let timer: NodeJS.Timeout | null = null;
+    const timeout = new Promise<void>((resolve) => {
+      timer = setTimeout(resolve, Math.max(0, finiteInteger(timeoutMs, DEFAULT_SHUTDOWN_TIMEOUT_MS)));
+    });
+    await Promise.race([this.drain(), timeout]);
+    if (timer) {
+      clearTimeout(timer);
+    }
+  }
+
+  public getStatus(): NotificationOutboxStatus {
+    return {
+      queued: this.events.length,
+      lastSuccessAt: this.lastSuccessAt,
+      lastFailureAt: this.lastFailureAt
+    };
+  }
+
+  private runExclusive(operation: () => Promise<void>): Promise<void> {
+    const result = this.operationChain.then(operation, operation);
+    this.operationChain = result.catch(() => {});
+    return result;
+  }
+
+  private scheduleDrain(delayMs: number): void {
+    if (this.shutdownRequested) {
+      return;
+    }
+    this.clearRetryTimer();
+    this.retryTimer = setTimeout(() => {
+      this.retryTimer = null;
+      void this.drain().catch(() => {});
+    }, delayMs);
+    this.retryTimer.unref?.();
+  }
+
+  private clearRetryTimer(): void {
+    if (this.retryTimer) {
+      clearTimeout(this.retryTimer);
+      this.retryTimer = null;
+    }
+  }
+
+  private load(): void {
+    try {
+      if (!fs.existsSync(this.filePath)) {
+        return;
+      }
+      const parsed = JSON.parse(fs.readFileSync(this.filePath, "utf8")) as Partial<PersistedNotificationOutbox>;
+      this.events = Array.isArray(parsed.events)
+        ? parsed.events.flatMap((event) => {
+          const normalized = sanitizeEvent(event);
+          return normalized ? [normalized] : [];
+        })
+        : [];
+      this.lastSuccessAt = finiteInteger(parsed.lastSuccessAt);
+      this.lastFailureAt = finiteInteger(parsed.lastFailureAt);
+      this.enforceLimits(this.clock());
+    } catch {
+      this.events = [];
+      this.lastSuccessAt = 0;
+      this.lastFailureAt = 0;
+    }
+  }
+
+  private enforceLimits(now: number): void {
+    this.events = this.events.filter((event) => event.expiresAt > now);
+    while (this.events.length > MAX_EVENTS) {
+      const successIndex = oldestIndex(this.events, (event) => event.priority === "success");
+      const removeIndex = successIndex >= 0 ? successIndex : oldestIndex(this.events, () => true);
+      this.events.splice(removeIndex, 1);
+    }
+  }
+
+  private async persist(now: number): Promise<void> {
+    this.enforceLimits(now);
+    await fsp.mkdir(path.dirname(this.filePath), { recursive: true });
+    const tempPath = `${this.filePath}.tmp`;
+    const state: PersistedNotificationOutbox = {
+      version: 1,
+      events: this.events,
+      lastSuccessAt: this.lastSuccessAt,
+      lastFailureAt: this.lastFailureAt
+    };
+    try {
+      await fsp.writeFile(tempPath, JSON.stringify(state), "utf8");
+      await fsp.rename(tempPath, this.filePath);
+    } catch (error) {
+      await fsp.rm(tempPath, { force: true }).catch(() => {});
+      throw error;
+    }
+  }
+}
diff --git a/src/main/notify.ts b/src/main/notify.ts
index 9f8c0b4..5e84ec5 100644
--- a/src/main/notify.ts
+++ b/src/main/notify.ts
@@ -1,17 +1,45 @@
 import { logger } from "./logger";
 
-export interface NotifyPayload {
-  title: string;
-  message: string;
-  mention?: string;
-}
+export interface NotifyPayload {
+  title: string;
+  message: string;
+  mention?: string;
+  color?: number;
+  fields?: DiscordEmbedFieldPayload[];
+  timestamp?: number | string;
+}
+
+export interface DiscordEmbedFieldPayload {
+  name: string;
+  value: string;
+  inline?: boolean;
+}
+
+export interface DiscordEmbedPayload {
+  title: string;
+  description: string;
+  color: number;
+  fields: Array<{
+    name: string;
+    value: string;
+    inline: boolean;
+  }>;
+  timestamp?: string;
+}
 
 const NOTIFY_TIMEOUT_MS = 5000;
-const WEBHOOK_USERNAME = "Real-Debrid Downloader";
+const WEBHOOK_USERNAME = "Multi-Debrid Downloader";
 const MIN_SEND_GAP_MS = 450;
 const RETRY_DELAYS_MS = [1000, 2500];
 const RATE_LIMIT_MAX_WAIT_MS = 15_000;
-const CONTENT_MAX_CHARS = 2000;
+const CONTENT_MAX_CHARS = 2000;
+const EMBED_TITLE_MAX_CHARS = 256;
+const EMBED_DESCRIPTION_MAX_CHARS = 4096;
+const EMBED_FIELD_NAME_MAX_CHARS = 256;
+const EMBED_FIELD_VALUE_MAX_CHARS = 1024;
+const EMBED_FIELDS_MAX = 25;
+const EMBED_TOTAL_MAX_CHARS = 6000;
+const DEFAULT_EMBED_COLOR = 0x2f81f7;
 
 export function isNotifyUrlValid(url: string): boolean {
   return /^https?:\/\/\S+$/i.test(String(url || "").trim());
@@ -32,7 +60,7 @@ export function normalizeDiscordMention(raw: string): string {
 
 // Discord counts the limit itself; slicing UTF-16 units can split a surrogate
 // pair at the boundary, which Discord rejects as invalid content.
-export function truncateContent(content: string, maxChars = CONTENT_MAX_CHARS): string {
+export function truncateContent(content: string, maxChars = CONTENT_MAX_CHARS): string {
   if (content.length <= maxChars) {
     return content;
   }
@@ -41,21 +69,73 @@ export function truncateContent(content: string, maxChars = CONTENT_MAX_CHARS):
   if (last >= 0xd800 && last <= 0xdbff) {
     cut = cut.slice(0, -1);
   }
-  return cut;
-}
-
-export function buildNotifyRequest(url: string, payload: NotifyPayload): { url: string; init: RequestInit } {
-  const mention = normalizeDiscordMention(payload.mention || "");
-  const content = truncateContent(`${mention ? `${mention} ` : ""}**${payload.title}**\n${payload.message}`);
-  return {
-    url: String(url || "").trim(),
-    init: {
-      method: "POST",
-      headers: { "Content-Type": "application/json" },
-      body: JSON.stringify({ username: WEBHOOK_USERNAME, content })
-    }
-  };
-}
+  return cut;
+}
+
+function normalizeTimestamp(value: number | string | undefined): string | undefined {
+  if (value === undefined) {
+    return undefined;
+  }
+  const date = new Date(value);
+  return Number.isFinite(date.getTime()) ? date.toISOString() : undefined;
+}
+
+function normalizeEmbedColor(value: number | undefined): number {
+  if (!Number.isFinite(value)) {
+    return DEFAULT_EMBED_COLOR;
+  }
+  return Math.max(0, Math.min(0xffffff, Math.floor(value as number)));
+}
+
+function buildDiscordEmbed(payload: NotifyPayload): DiscordEmbedPayload {
+  let remaining = EMBED_TOTAL_MAX_CHARS;
+  const title = truncateContent(String(payload.title || ""), Math.min(EMBED_TITLE_MAX_CHARS, remaining));
+  remaining -= title.length;
+  const description = truncateContent(String(payload.message || ""), Math.min(EMBED_DESCRIPTION_MAX_CHARS, remaining));
+  remaining -= description.length;
+  const fields: DiscordEmbedPayload["fields"] = [];
+  for (const field of (payload.fields || []).slice(0, EMBED_FIELDS_MAX)) {
+    if (remaining < 2) {
+      break;
+    }
+    const name = truncateContent(String(field.name || ""), Math.min(EMBED_FIELD_NAME_MAX_CHARS, remaining - 1));
+    if (!name) {
+      continue;
+    }
+    remaining -= name.length;
+    const value = truncateContent(String(field.value || ""), Math.min(EMBED_FIELD_VALUE_MAX_CHARS, remaining));
+    if (!value) {
+      remaining += name.length;
+      continue;
+    }
+    remaining -= value.length;
+    fields.push({ name, value, inline: Boolean(field.inline) });
+  }
+  const timestamp = normalizeTimestamp(payload.timestamp);
+  return {
+    title,
+    description,
+    color: normalizeEmbedColor(payload.color),
+    fields,
+    ...(timestamp ? { timestamp } : {})
+  };
+}
+
+export function buildNotifyRequest(url: string, payload: NotifyPayload): { url: string; init: RequestInit } {
+  const mention = normalizeDiscordMention(payload.mention || "");
+  return {
+    url: String(url || "").trim(),
+    init: {
+      method: "POST",
+      headers: { "Content-Type": "application/json" },
+      body: JSON.stringify({
+        username: WEBHOOK_USERNAME,
+        content: truncateContent(mention),
+        embeds: [buildDiscordEmbed(payload)]
+      })
+    }
+  };
+}
 
 function delayMs(ms: number): Promise<void> {
   return new Promise((resolve) => setTimeout(resolve, ms));
diff --git a/src/main/storage.ts b/src/main/storage.ts
index 565043e..69cf2f0 100644
--- a/src/main/storage.ts
+++ b/src/main/storage.ts
@@ -696,22 +696,24 @@ export function normalizeSettings(settings: AppSettings): AppSettings {
 }
 
 export interface StoragePaths {
-  baseDir: string;
-  configFile: string;
-  sessionFile: string;
+  baseDir: string;
+  configFile: string;
+  sessionFile: string;
   historyFile: string;
   statisticsFile: string;
-}
+  notificationOutboxFile: string;
+}
 
 export function createStoragePaths(baseDir: string): StoragePaths {
   return {
     baseDir,
-    configFile: path.join(baseDir, "rd_downloader_config.json"),
-    sessionFile: path.join(baseDir, "rd_session_state.json"),
+    configFile: path.join(baseDir, "rd_downloader_config.json"),
+    sessionFile: path.join(baseDir, "rd_session_state.json"),
     historyFile: path.join(baseDir, "rd_history.json"),
-    statisticsFile: path.join(baseDir, "rd_statistics.json")
-  };
-}
+    statisticsFile: path.join(baseDir, "rd_statistics.json"),
+    notificationOutboxFile: path.join(baseDir, "rd_notification_outbox.json")
+  };
+}
 
 function ensureBaseDir(baseDir: string): void {
   try {
diff --git a/tests/notification-outbox.test.ts b/tests/notification-outbox.test.ts
new file mode 100644
index 0000000..b358099
--- /dev/null
+++ b/tests/notification-outbox.test.ts
@@ -0,0 +1,195 @@
+import fs from "node:fs";
+import fsp from "node:fs/promises";
+import os from "node:os";
+import path from "node:path";
+import { afterEach, describe, expect, it, vi } from "vitest";
+import { NotificationEvent, NotificationOutbox } from "../src/main/notification-outbox";
+
+const tempDirs: string[] = [];
+
+afterEach(() => {
+  vi.useRealTimers();
+  for (const dir of tempDirs.splice(0)) {
+    fs.rmSync(dir, { recursive: true, force: true });
+  }
+});
+
+function createOutboxFile(): string {
+  const dir = fs.mkdtempSync(path.join(os.tmpdir(), "mdd-notification-outbox-"));
+  tempDirs.push(dir);
+  return path.join(dir, "notification-outbox.json");
+}
+
+function event(id: string, overrides: Partial<NotificationEvent> = {}): NotificationEvent {
+  return {
+    id,
+    type: "package_failed",
+    priority: "error",
+    createdAt: 1000,
+    expiresAt: 86401000,
+    attempts: 0,
+    nextAttemptAt: 1000,
+    payload: {
+      title: "Paket fehlgeschlagen",
+      description: "Eine Datei ist fehlgeschlagen.",
+      fields: []
+    },
+    ...overrides
+  };
+}
+
+function persisted(filePath: string): { events: NotificationEvent[]; lastSuccessAt: number; lastFailureAt: number } {
+  return JSON.parse(fs.readFileSync(filePath, "utf8")) as { events: NotificationEvent[]; lastSuccessAt: number; lastFailureAt: number };
+}
+
+describe("NotificationOutbox", () => {
+  it("sends due events serially in stable enqueue order and removes each success", async () => {
+    const filePath = createOutboxFile();
+    const sent: string[] = [];
+    const outbox = new NotificationOutbox({
+      filePath,
+      now: () => 1000,
+      send: async (queuedEvent) => {
+        sent.push(queuedEvent.id);
+        return true;
+      }
+    });
+
+    await outbox.enqueue(event("first"));
+    await outbox.enqueue(event("second", { createdAt: 900 }));
+    await outbox.enqueue(event("third"));
+    await outbox.drain(1000);
+
+    expect(sent).toEqual(["first", "second", "third"]);
+    expect(outbox.getStatus()).toEqual({ queued: 0, lastSuccessAt: 1000, lastFailureAt: 0 });
+    expect(persisted(filePath).events).toEqual([]);
+  });
+
+  it("backs off a failed event without allowing later events to overtake it", async () => {
+    const filePath = createOutboxFile();
+    const outcomes = [false, true, true];
+    const sent: string[] = [];
+    const outbox = new NotificationOutbox({
+      filePath,
+      now: () => 1000,
+      send: async (queuedEvent) => {
+        sent.push(queuedEvent.id);
+        return outcomes.shift() ?? true;
+      }
+    });
+
+    await outbox.enqueue(event("first"));
+    await outbox.enqueue(event("second"));
+    await outbox.drain(1000);
+    expect(sent).toEqual(["first"]);
+    expect(persisted(filePath).events[0]).toMatchObject({ id: "first", attempts: 1, nextAttemptAt: 2000 });
+    expect(outbox.getStatus()).toEqual({ queued: 2, lastSuccessAt: 0, lastFailureAt: 1000 });
+
+    await outbox.drain(1999);
+    expect(sent).toEqual(["first"]);
+    await outbox.drain(2000);
+    expect(sent).toEqual(["first", "first", "second"]);
+  });
+
+  it("automatically drains new events and retries them at the persisted deadline", async () => {
+    vi.useFakeTimers();
+    vi.setSystemTime(1000);
+    const filePath = createOutboxFile();
+    const outcomes = [false, true];
+    const send = vi.fn().mockImplementation(async () => outcomes.shift() ?? true);
+    const outbox = new NotificationOutbox({ filePath, send, autoDrain: true });
+
+    await outbox.enqueue(event("automatic"));
+    await vi.advanceTimersByTimeAsync(0);
+    await outbox.drain(1000);
+    expect(send).toHaveBeenCalledTimes(1);
+    expect(outbox.getStatus().queued).toBe(1);
+
+    await vi.advanceTimersByTimeAsync(999);
+    expect(send).toHaveBeenCalledTimes(1);
+    await vi.advanceTimersByTimeAsync(1);
+    expect(send).toHaveBeenCalledTimes(2);
+    expect(outbox.getStatus().queued).toBe(0);
+  });
+
+  it("persists through a temporary file and atomic rename", async () => {
+    const filePath = createOutboxFile();
+    const rename = vi.spyOn(fsp, "rename");
+    try {
+      const outbox = new NotificationOutbox({ filePath, send: async () => true, now: () => 1000 });
+      await outbox.enqueue(event("atomic"));
+      expect(rename).toHaveBeenCalledWith(`${filePath}.tmp`, filePath);
+      expect(fs.existsSync(`${filePath}.tmp`)).toBe(false);
+      expect(persisted(filePath).events.map((queuedEvent) => queuedEvent.id)).toEqual(["atomic"]);
+    } finally {
+      rename.mockRestore();
+    }
+  });
+
+  it("drops expired events before persisting or sending", async () => {
+    const filePath = createOutboxFile();
+    const send = vi.fn().mockResolvedValue(true);
+    const outbox = new NotificationOutbox({ filePath, send, now: () => 2000 });
+
+    await outbox.enqueue(event("expired", { expiresAt: 1999 }));
+    await outbox.drain(2000);
+
+    expect(send).not.toHaveBeenCalled();
+    expect(outbox.getStatus().queued).toBe(0);
+    expect(persisted(filePath).events).toEqual([]);
+  });
+
+  it("caps the queue at 250 and evicts the oldest success before errors", async () => {
+    const filePath = createOutboxFile();
+    const outbox = new NotificationOutbox({ filePath, send: async () => true, now: () => 1000 });
+    for (let index = 0; index < 249; index += 1) {
+      await outbox.enqueue(event(`error-${index}`, { createdAt: 1000 + index }));
+    }
+    await outbox.enqueue(event("success-old", { type: "package_completed", priority: "success", createdAt: 500 }));
+    await outbox.enqueue(event("success-new", { type: "package_completed", priority: "success", createdAt: 2000 }));
+
+    const ids = persisted(filePath).events.map((queuedEvent) => queuedEvent.id);
+    expect(ids).toHaveLength(250);
+    expect(ids).not.toContain("success-old");
+    expect(ids).toContain("success-new");
+    expect(ids.filter((id) => id.startsWith("error-"))).toHaveLength(249);
+  });
+
+  it("never persists webhook or mention fields supplied outside the event contract", async () => {
+    const filePath = createOutboxFile();
+    const outbox = new NotificationOutbox({ filePath, send: async () => true, now: () => 1000 });
+    const unsafe = {
+      ...event("safe"),
+      url: "https://discord.example.test/private-webhook",
+      mention: "@private",
+      payload: {
+        ...event("safe").payload,
+        url: "https://discord.example.test/nested-private-webhook",
+        mention: "@nested-private"
+      }
+    } as unknown as NotificationEvent;
+
+    await outbox.enqueue(unsafe);
+
+    const raw = fs.readFileSync(filePath, "utf8");
+    expect(raw).not.toContain("private-webhook");
+    expect(raw).not.toContain("@private");
+    expect(persisted(filePath).events[0]).toEqual(event("safe"));
+  });
+
+  it("returns after the default three-second shutdown budget when sending hangs", async () => {
+    vi.useFakeTimers();
+    const filePath = createOutboxFile();
+    const outbox = new NotificationOutbox({ filePath, send: async () => new Promise<boolean>(() => {}), now: () => 1000 });
+    await outbox.enqueue(event("hanging"));
+
+    let completed = false;
+    const draining = outbox.drainForShutdown().then(() => { completed = true; });
+    await vi.advanceTimersByTimeAsync(2999);
+    expect(completed).toBe(false);
+    await vi.advanceTimersByTimeAsync(1);
+    await draining;
+    expect(completed).toBe(true);
+    expect(outbox.getStatus().queued).toBe(1);
+  });
+});
diff --git a/tests/notify.test.ts b/tests/notify.test.ts
index e398714..a084e0b 100644
--- a/tests/notify.test.ts
+++ b/tests/notify.test.ts
@@ -52,26 +52,66 @@ describe("truncateContent", () => {
   });
 });
 
-describe("buildNotifyRequest", () => {
-  it("builds a Discord-compatible JSON webhook POST (bold title + message as content)", () => {
-    const req = buildNotifyRequest(` ${WEBHOOK} `, { title: "✅ Paket fertig", message: "Show.S01\n5 Datei(en)" });
-    expect(req.url).toBe(WEBHOOK);
-    expect(req.init.method).toBe("POST");
-    expect(req.init.headers).toMatchObject({ "Content-Type": "application/json" });
-    const body = JSON.parse(String(req.init.body));
-    expect(body.content).toBe("**✅ Paket fertig**\nShow.S01\n5 Datei(en)");
-    expect(body.username).toBe("Real-Debrid Downloader");
-  });
-  it("prepends the mention so Discord pings (bare ID gets wrapped)", () => {
-    const req = buildNotifyRequest(WEBHOOK, { title: "T", message: "M", mention: "123456789012345678" });
-    const body = JSON.parse(String(req.init.body));
-    expect(body.content).toBe("<@123456789012345678> **T**\nM");
-  });
-  it("sends no mention prefix when the field is empty", () => {
-    const req = buildNotifyRequest(WEBHOOK, { title: "T", message: "M", mention: "" });
-    const body = JSON.parse(String(req.init.body));
-    expect(body.content).toBe("**T**\nM");
-  });
+describe("buildNotifyRequest", () => {
+  it("builds a bounded Discord embed with the product username", () => {
+    const req = buildNotifyRequest(` ${WEBHOOK} `, {
+      title: "Paket fehlgeschlagen",
+      message: "Eine Datei konnte nicht verarbeitet werden.",
+      color: 0xe74c3c,
+      fields: [
+        { name: "Ergebnis", value: "Fehlgeschlagen", inline: true },
+        { name: "Dateien", value: "0 erfolgreich, 1 fehlgeschlagen", inline: true }
+      ],
+      timestamp: 1000
+    });
+    expect(req.url).toBe(WEBHOOK);
+    expect(req.init.method).toBe("POST");
+    expect(req.init.headers).toMatchObject({ "Content-Type": "application/json" });
+    const body = JSON.parse(String(req.init.body));
+    expect(body).toEqual({
+      username: "Multi-Debrid Downloader",
+      content: "",
+      embeds: [{
+        title: "Paket fehlgeschlagen",
+        description: "Eine Datei konnte nicht verarbeitet werden.",
+        color: 0xe74c3c,
+        fields: [
+          { name: "Ergebnis", value: "Fehlgeschlagen", inline: true },
+          { name: "Dateien", value: "0 erfolgreich, 1 fehlgeschlagen", inline: true }
+        ],
+        timestamp: "1970-01-01T00:00:01.000Z"
+      }]
+    });
+  });
+  it("prepends the mention so Discord pings (bare ID gets wrapped)", () => {
+    const req = buildNotifyRequest(WEBHOOK, { title: "T", message: "M", mention: "123456789012345678" });
+    const body = JSON.parse(String(req.init.body));
+    expect(body.content).toBe("<@123456789012345678>");
+    expect(body.embeds[0]).toMatchObject({ title: "T", description: "M" });
+  });
+  it("sends no mention prefix when the field is empty", () => {
+    const req = buildNotifyRequest(WEBHOOK, { title: "T", message: "M", mention: "" });
+    const body = JSON.parse(String(req.init.body));
+    expect(body.content).toBe("");
+  });
+  it("enforces Discord title, description, field, and total embed limits", () => {
+    const req = buildNotifyRequest(WEBHOOK, {
+      title: "T".repeat(400),
+      message: "M".repeat(5000),
+      fields: Array.from({ length: 30 }, (_, index) => ({
+        name: `${index}-${"N".repeat(300)}`,
+        value: "V".repeat(1400)
+      }))
+    });
+    const body = JSON.parse(String(req.init.body));
+    const embed = body.embeds[0] as { title: string; description: string; fields: Array<{ name: string; value: string }> };
+    expect(embed.title.length).toBeLessThanOrEqual(256);
+    expect(embed.description.length).toBeLessThanOrEqual(4096);
+    expect(embed.fields.length).toBeLessThanOrEqual(25);
+    expect(embed.fields.every((field) => field.name.length <= 256 && field.value.length <= 1024)).toBe(true);
+    const total = embed.title.length + embed.description.length + embed.fields.reduce((sum, field) => sum + field.name.length + field.value.length, 0);
+    expect(total).toBeLessThanOrEqual(6000);
+  });
 });
 
 describe("sendNotification", () => {
@@ -104,20 +144,20 @@ describe("sendNotification", () => {
     await expect(sendNotification(WEBHOOK, { title: "T", message: "M" }, fetchFn, noSleep)).resolves.toBe(false);
     expect(fetchFn).toHaveBeenCalledTimes(1);
   });
-  it("serializes concurrent sends in order (burst protection)", async () => {
-    const order: string[] = [];
-    const fetchFn = vi.fn().mockImplementation(async (_url: string, init: RequestInit) => {
-      order.push(JSON.parse(String(init.body)).content);
-      return new Response(null, { status: 204 });
-    });
+  it("serializes concurrent sends in order (burst protection)", async () => {
+    const order: string[] = [];
+    const fetchFn = vi.fn().mockImplementation(async (_url: string, init: RequestInit) => {
+      order.push(JSON.parse(String(init.body)).embeds[0].title);
+      return new Response(null, { status: 204 });
+    });
     const sends = [
       sendNotification(WEBHOOK, { title: "1", message: "" }, fetchFn, noSleep),
       sendNotification(WEBHOOK, { title: "2", message: "" }, fetchFn, noSleep),
       sendNotification(WEBHOOK, { title: "3", message: "" }, fetchFn, noSleep)
-    ];
-    await expect(Promise.all(sends)).resolves.toEqual([true, true, true]);
-    expect(order).toEqual(["**1**\n", "**2**\n", "**3**\n"]);
-  });
+    ];
+    await expect(Promise.all(sends)).resolves.toEqual([true, true, true]);
+    expect(order).toEqual(["1", "2", "3"]);
+  });
   it("does not call fetch for an invalid URL", async () => {
     const fetchFn = vi.fn();
     await expect(sendNotification("", { title: "T", message: "M" }, fetchFn, noSleep)).resolves.toBe(false);
diff --git a/tests/session-restart-loss.test.ts b/tests/session-restart-loss.test.ts
index 39bb814..df1b64d 100644
Binary files a/tests/session-restart-loss.test.ts and b/tests/session-restart-loss.test.ts differ