diff --git a/.env.example b/.env.example
index efc18b7..6c00e3a 100644
--- a/.env.example
+++ b/.env.example
@@ -2,8 +2,6 @@ NODE_ENV=production
 APP_PORT=3999
 APP_NAME="NestJS API"
 API_PREFIX=api
-APP_FALLBACK_LANGUAGE=en
-APP_HEADER_LANGUAGE=x-custom-lang
 FRONTEND_DOMAIN=http://localhost:3999
 BACKEND_DOMAIN=http://localhost:3999
 
diff --git a/docs/superpowers/plans/2026-07-31-mail-versand.md b/docs/superpowers/plans/2026-07-31-mail-versand.md
new file mode 100644
index 0000000..92d75e8
--- /dev/null
+++ b/docs/superpowers/plans/2026-07-31-mail-versand.md
@@ -0,0 +1,664 @@
+# Mailversand reparieren + Templates neu gestalten — Implementation Plan
+
+> **For agentic workers:** REQUIRED SUB-SKILL: Use superpowers:subagent-driven-development (recommended) or superpowers:executing-plans to implement this plan task-by-task. Steps use checkbox (`- [ ]`) syntax for tracking.
+
+**Goal:** Mailversand für Registrierung und Passwort-vergessen im NestJS-Backend
+(`myteamwallet_backend`) wieder funktionsfähig machen, das mail-only `nestjs-i18n` Setup
+entfernen (Texte direkt auf Deutsch), und die zwei Handlebars-Templates in einem zu
+"TeamWallet" (Grün `#2e7d32`) passenden, hübschen Design neu bauen.
+
+**Architecture:** `MailService` (`@nestjs-modules/mailer` + Nodemailer + Handlebars) bleibt die
+zentrale Versandstelle. Der Bug ist ein totes `return;` vor `sendMail(...)` in beiden Methoden —
+Fix ist ein reiner Code-Fix, keine Config-Änderung nötig (`.env` ist bereits lokal korrekt
+befüllt). `nestjs-i18n` wird komplett entfernt, deutsche Texte wandern direkt in die
+`.hbs`-Templates bzw. als String-Literale in `mail.service.ts`. Die zwei Templates teilen sich
+ein gemeinsames Handlebars-Block-Partial (`partials/layout.hbs`) für Header/Footer, um
+Duplikation zu vermeiden.
+
+**Tech Stack:** NestJS 9, `@nestjs-modules/mailer` 1.8.1 (Nodemailer 6.8.0), Handlebars 4.7.7,
+Jest 29 (Unit-Tests), TypeScript 4.8.
+
+## Global Constraints
+
+- Nur Deutsch — keine mehrsprachige i18n-Infrastruktur für Mails, keine Sprachdateien.
+- `nestjs-i18n` wird vollständig aus dem Backend entfernt (Modul, Dependency, `src/i18n/`).
+- Branding: Akzentfarbe `#2e7d32` (Grün), Textwordmark „TeamWallet" (kein Bild-Logo), Roboto mit
+  Fallback-Stack `Roboto, Helvetica, Arial, sans-serif`, abgerundete Card-Optik (~12px Radius),
+  `max-width: 600px`, Inline-CSS-safe (die `HandlebarsAdapter` inlined `<style>`-CSS automatisch
+  via `inline-css`, `inlineCssEnabled` ist standardmäßig `true`).
+- Kein MJML, kein Build-Pipeline-Zusatz für Templates.
+- `.env` (in `myteamwallet_backend/.env`) wird **nicht** verändert — existiert bereits mit
+  gültigen Werten.
+- Kein neuer e2e-/MailDev-Aufbau — Verifikation über Unit-Tests plus einen manuellen echten
+  Testversand (siehe Task 4).
+
+---
+
+### Task 1: Bugfix `MailService` + Vornamen-Personalisierung
+
+**Files:**
+- Modify: `myteamwallet_backend/src/mail/mail.service.ts`
+- Modify: `myteamwallet_backend/src/auth/auth.service.ts:191-196` (register) und `:246-251`
+  (forgotPassword)
+- Test: `myteamwallet_backend/src/mail/mail.service.spec.ts` (neu)
+
+**Interfaces:**
+- Produces: `MailService.userSignUp(mailData: MailData<{ hash: string; firstName?: string | null }>): Promise<void>`
+- Produces: `MailService.forgotPassword(mailData: MailData<{ hash: string; firstName?: string | null }>): Promise<void>`
+- Beide senden über `this.mailerService.sendMail({ to, subject, text, template, context })` mit
+  `context` immer inkl. der Keys `title`, `year`, `firstName`, `url`, `actionTitle` (Task 3
+  Templates lesen genau diese Keys).
+
+- [ ] **Step 1: Failing Test schreiben**
+
+Datei `myteamwallet_backend/src/mail/mail.service.spec.ts`:
+
+```typescript
+import { ConfigService } from '@nestjs/config';
+import { MailerService } from '@nestjs-modules/mailer';
+import { MailService } from './mail.service';
+
+describe('MailService', () => {
+  let service: MailService;
+  let sendMail: jest.Mock;
+  let configGet: jest.Mock;
+
+  beforeEach(() => {
+    sendMail = jest.fn().mockResolvedValue(undefined);
+    configGet = jest.fn().mockReturnValue('https://app.example.com');
+
+    service = new MailService(
+      { sendMail } as unknown as MailerService,
+      { get: configGet } as unknown as ConfigService,
+    );
+  });
+
+  it('sends the activation mail with the confirm-email link', async () => {
+    await service.userSignUp({
+      to: 'user@example.com',
+      data: { hash: 'abc123', firstName: 'Max' },
+    });
+
+    expect(sendMail).toHaveBeenCalledTimes(1);
+    const call = sendMail.mock.calls[0][0];
+    expect(call.to).toBe('user@example.com');
+    expect(call.template).toBe('activation');
+    expect(call.context.url).toBe(
+      'https://app.example.com/confirm-email/abc123',
+    );
+    expect(call.context.firstName).toBe('Max');
+  });
+
+  it('sends the reset-password mail with the password-change link', async () => {
+    await service.forgotPassword({
+      to: 'user@example.com',
+      data: { hash: 'xyz789', firstName: 'Erika' },
+    });
+
+    expect(sendMail).toHaveBeenCalledTimes(1);
+    const call = sendMail.mock.calls[0][0];
+    expect(call.to).toBe('user@example.com');
+    expect(call.template).toBe('reset-password');
+    expect(call.context.url).toBe(
+      'https://app.example.com/password-change/xyz789',
+    );
+    expect(call.context.firstName).toBe('Erika');
+  });
+
+  it('works without a firstName (optional personalization)', async () => {
+    await service.userSignUp({
+      to: 'user@example.com',
+      data: { hash: 'abc123' },
+    });
+
+    const call = sendMail.mock.calls[0][0];
+    expect(call.context.firstName).toBeUndefined();
+  });
+});
+```
+
+- [ ] **Step 2: Test laufen lassen, erwartetes Scheitern bestätigen**
+
+Run: `cd myteamwallet_backend && npx jest mail.service.spec.ts`
+Expected: FAIL — `MailService` erwartet aktuell drei Constructor-Parameter (`I18n`,
+`MailerService`, `ConfigService`), der Test übergibt nur zwei, und selbst bei passendem Aufruf
+würde `sendMail` wegen des toten `return;` nie aufgerufen. Der Test schlägt fehl (z. B.
+`expect(sendMail).toHaveBeenCalledTimes(1)` erhält `0`, oder ein `TypeError` beim Zugriff auf
+`this.i18n.t`).
+
+- [ ] **Step 3: `mail.service.ts` neu implementieren**
+
+Datei `myteamwallet_backend/src/mail/mail.service.ts` komplett ersetzen:
+
+```typescript
+import { MailerService } from '@nestjs-modules/mailer';
+import { Injectable } from '@nestjs/common';
+import { ConfigService } from '@nestjs/config';
+import { MailData } from './interfaces/mail-data.interface';
+
+@Injectable()
+export class MailService {
+  constructor(
+    private mailerService: MailerService,
+    private configService: ConfigService,
+  ) {}
+
+  async userSignUp(
+    mailData: MailData<{ hash: string; firstName?: string | null }>,
+  ) {
+    const actionTitle = 'E-Mail bestätigen';
+    const url = `${this.configService.get('app.frontendDomain')}/confirm-email/${
+      mailData.data.hash
+    }`;
+
+    await this.mailerService.sendMail({
+      to: mailData.to,
+      subject: 'Bestätige deine E-Mail-Adresse',
+      text: `${url} ${actionTitle}`,
+      template: 'activation',
+      context: {
+        title: 'Bestätige deine E-Mail-Adresse',
+        year: new Date().getFullYear(),
+        firstName: mailData.data.firstName,
+        url,
+        actionTitle,
+      },
+    });
+  }
+
+  async forgotPassword(
+    mailData: MailData<{ hash: string; firstName?: string | null }>,
+  ) {
+    const actionTitle = 'Passwort zurücksetzen';
+    const url = `${this.configService.get('app.frontendDomain')}/password-change/${
+      mailData.data.hash
+    }`;
+
+    await this.mailerService.sendMail({
+      to: mailData.to,
+      subject: actionTitle,
+      text: `${url} ${actionTitle}`,
+      template: 'reset-password',
+      context: {
+        title: actionTitle,
+        year: new Date().getFullYear(),
+        firstName: mailData.data.firstName,
+        url,
+        actionTitle,
+      },
+    });
+  }
+}
+```
+
+- [ ] **Step 4: Test laufen lassen, Erfolg bestätigen**
+
+Run: `cd myteamwallet_backend && npx jest mail.service.spec.ts`
+Expected: PASS — alle 3 Tests grün.
+
+- [ ] **Step 5: `auth.service.ts` — Vornamen mitgeben**
+
+In `myteamwallet_backend/src/auth/auth.service.ts`, die zwei bestehenden Aufrufstellen anpassen
+(nur die `data`-Objekte erweitern, sonst nichts ändern):
+
+Zeilen 191-196 (in `register()`, `user` ist zu diesem Zeitpunkt bereits erstellt):
+
+```typescript
+    await this.mailService.userSignUp({
+      to: user.email,
+      data: {
+        hash,
+        firstName: user.firstName,
+      },
+    });
+```
+
+Zeilen 246-251 (in `forgotPassword()`, im `else`-Zweig nach `user` lookup):
+
+```typescript
+      await this.mailService.forgotPassword({
+        to: email,
+        data: {
+          hash,
+          firstName: user.firstName,
+        },
+      });
+```
+
+- [ ] **Step 6: TypeScript-Build prüfen**
+
+Run: `cd myteamwallet_backend && npm run build`
+Expected: Build erfolgreich, keine Type-Fehler (insbesondere keine Fehler zu `firstName` an den
+beiden Aufrufstellen).
+
+- [ ] **Step 7: Commit**
+
+```bash
+git add myteamwallet_backend/src/mail/mail.service.ts myteamwallet_backend/src/mail/mail.service.spec.ts myteamwallet_backend/src/auth/auth.service.ts
+git commit -m "fix(mail): remove dead return before sendMail, add firstName personalization"
+```
+
+---
+
+### Task 2: `nestjs-i18n` vollständig entfernen
+
+**Files:**
+- Modify: `myteamwallet_backend/src/app.module.ts`
+- Modify: `myteamwallet_backend/src/config/app.config.ts`
+- Delete: `myteamwallet_backend/src/i18n/` (kompletter Ordner: `en/common.json`,
+  `en/confirm-email.json`, `en/reset-password.json`)
+- Modify: `myteamwallet_backend/package.json`, `myteamwallet_backend/package-lock.json`
+
+**Interfaces:**
+- Consumes: nichts aus Task 1.
+- Produces: keine neuen Symbole — reine Entfernung. Spätere Tasks verlassen sich nicht auf
+  `nestjs-i18n`.
+
+- [ ] **Step 1: `src/i18n/` Ordner löschen**
+
+Run: `cd myteamwallet_backend && rm -rf src/i18n`
+
+- [ ] **Step 2: `app.module.ts` bereinigen**
+
+In `myteamwallet_backend/src/app.module.ts`:
+
+Import-Block (Zeilen 1-30) — `import * as path from 'path';` (Zeile 9), `import { I18nModule } from 'nestjs-i18n/dist/i18n.module';` (Zeile 13) und `import { HeaderResolver } from 'nestjs-i18n';` (Zeile 14) entfernen; `import { ConfigModule, ConfigService } from '@nestjs/config';` (Zeile 11) zu `import { ConfigModule } from '@nestjs/config';` ändern (kein anderer Verbraucher von `ConfigService` mehr in dieser Datei). Ergebnis:
+
+```typescript
+import { Module } from '@nestjs/common';
+import { UsersModule } from './users/users.module';
+import { AuthModule } from './auth/auth.module';
+import databaseConfig from './config/database.config';
+import authConfig from './config/auth.config';
+import appConfig from './config/app.config';
+import mailConfig from './config/mail.config';
+import fileConfig from './config/file.config';
+import { MailerModule } from '@nestjs-modules/mailer';
+import { ConfigModule } from '@nestjs/config';
+import { TypeOrmModule } from '@nestjs/typeorm';
+import { TypeOrmConfigService } from './database/typeorm-config.service';
+import { MailConfigService } from './mail/mail-config.service';
+import { ForgotModule } from './forgot/forgot.module';
+import { MailModule } from './mail/mail.module';
+import { DataSource } from 'typeorm';
+import { PlayersModule } from './players/players.module';
+import { TeamsModule } from './teams/teams.module';
+import { TransactionsModule } from './transactions/transactions.module';
+import { TeamSettingsModule } from './team-settings/team-settings.module';
+import { TeamWalletTransactionsModule } from './team-wallet-transactions/team-wallet-transactions.module';
+import { ServeStaticModule } from '@nestjs/serve-static';
+import { join } from 'path';
+import { LoggingModule } from './database/logging/logging.module';
+import { TranslateModule } from './translate/translate.module';
+import { PenaltyModule } from './penalty/penalty.module';
+```
+
+Im `@Module({ imports: [...] })` Array den kompletten `I18nModule.forRootAsync({...})` Block
+(bisher direkt nach `MailerModule.forRootAsync({...})`) entfernen, sodass `MailerModule` direkt
+von `ServeStaticModule` gefolgt wird:
+
+```typescript
+    MailerModule.forRootAsync({
+      useClass: MailConfigService,
+    }),
+    ServeStaticModule.forRoot({
+      rootPath: join(__dirname, '../client'),
+      exclude: ['*/api*'],
+    }),
+```
+
+- [ ] **Step 3: `app.config.ts` bereinigen**
+
+`myteamwallet_backend/src/config/app.config.ts` — Zeilen `fallbackLanguage` und
+`headerLanguage` entfernen (waren ausschließlich für `I18nModule` gedacht, kein anderer
+Konsument im Code):
+
+```typescript
+import { registerAs } from '@nestjs/config';
+
+export default registerAs('app', () => ({
+  nodeEnv: process.env.NODE_ENV,
+  name: process.env.APP_NAME,
+  workingDirectory: process.env.PWD || process.cwd(),
+  frontendDomain: process.env.FRONTEND_DOMAIN,
+  backendDomain: process.env.BACKEND_DOMAIN,
+  port: parseInt(process.env.APP_PORT || process.env.PORT, 10) || 3000,
+  apiPrefix: process.env.API_PREFIX || 'api',
+}));
+```
+
+- [ ] **Step 4: Dependency entfernen**
+
+Run: `cd myteamwallet_backend && npm uninstall nestjs-i18n`
+Expected: `package.json` und `package-lock.json` werden automatisch aktualisiert (Eintrag
+`"nestjs-i18n": "9.2.2"` verschwindet aus `dependencies`).
+
+- [ ] **Step 5: Keine verbleibenden Referenzen prüfen**
+
+Run: `cd myteamwallet_backend && grep -rn "nestjs-i18n\|I18nModule\|HeaderResolver\|I18nRequestScopeService" src/`
+Expected: keine Treffer (leere Ausgabe).
+
+- [ ] **Step 6: Build prüfen**
+
+Run: `cd myteamwallet_backend && npm run build`
+Expected: Build erfolgreich, keine Fehler zu fehlenden `nestjs-i18n`-Imports oder unbenutzten
+Imports.
+
+- [ ] **Step 7: Bestehende Unit-Tests laufen lassen**
+
+Run: `cd myteamwallet_backend && npm test`
+Expected: alle Tests grün, inkl. der in Task 1 hinzugefügten `mail.service.spec.ts`.
+
+- [ ] **Step 8: Commit**
+
+```bash
+git add myteamwallet_backend/src/app.module.ts myteamwallet_backend/src/config/app.config.ts myteamwallet_backend/package.json myteamwallet_backend/package-lock.json
+git status
+git add myteamwallet_backend/src/i18n
+git commit -m "chore(mail): remove nestjs-i18n, only ever used for the two mail templates"
+```
+
+(Der zweite `git add` erfasst die Löschung von `src/i18n/*` — je nach Git-Version reicht auch
+ein einzelnes `git add -A myteamwallet_backend/src/i18n myteamwallet_backend/src/app.module.ts myteamwallet_backend/src/config/app.config.ts myteamwallet_backend/package.json myteamwallet_backend/package-lock.json`.)
+
+---
+
+### Task 3: E-Mail-Templates neu gestalten
+
+**Files:**
+- Modify: `myteamwallet_backend/src/mail/mail-config.service.ts`
+- Create: `myteamwallet_backend/src/mail/mail-templates/partials/layout.hbs`
+- Modify: `myteamwallet_backend/src/mail/mail-templates/activation.hbs`
+- Modify: `myteamwallet_backend/src/mail/mail-templates/reset-password.hbs`
+- Test: `myteamwallet_backend/src/mail/mail-templates/mail-templates.spec.ts` (neu)
+
+**Interfaces:**
+- Consumes: Context-Keys aus Task 1 — `title`, `year`, `firstName`, `url`, `actionTitle`.
+- Produces: registriertes Handlebars-Partial `layout` (Name = Dateiname ohne Endung, da es
+  direkt in `partials/` liegt), eingebunden via `{{#> layout}} ... {{/layout}}` in beiden
+  Content-Templates.
+
+- [ ] **Step 1: Failing Test schreiben**
+
+Datei `myteamwallet_backend/src/mail/mail-templates/mail-templates.spec.ts`:
+
+```typescript
+import * as fs from 'fs';
+import * as path from 'path';
+import * as Handlebars from 'handlebars';
+
+describe('mail templates rendering', () => {
+  const templatesDir = __dirname;
+
+  beforeAll(() => {
+    const layoutSource = fs.readFileSync(
+      path.join(templatesDir, 'partials', 'layout.hbs'),
+      'utf-8',
+    );
+    Handlebars.registerPartial('layout', layoutSource);
+  });
+
+  const baseContext = {
+    title: 'Test-Betreff',
+    year: 2026,
+    firstName: 'Max',
+    url: 'https://app.example.com/confirm-email/abc123',
+    actionTitle: 'Jetzt bestätigen',
+  };
+
+  it('renders activation.hbs with greeting, link and button text', () => {
+    const source = fs.readFileSync(
+      path.join(templatesDir, 'activation.hbs'),
+      'utf-8',
+    );
+    const html = Handlebars.compile(source, { strict: true })(baseContext);
+
+    expect(html).toContain('TeamWallet');
+    expect(html).toContain('Hallo Max,');
+    expect(html).toContain(baseContext.url);
+    expect(html).toContain(baseContext.actionTitle);
+  });
+
+  it('renders reset-password.hbs with greeting, link and button text', () => {
+    const source = fs.readFileSync(
+      path.join(templatesDir, 'reset-password.hbs'),
+      'utf-8',
+    );
+    const html = Handlebars.compile(source, { strict: true })(baseContext);
+
+    expect(html).toContain('TeamWallet');
+    expect(html).toContain('Hallo Max,');
+    expect(html).toContain(baseContext.url);
+    expect(html).toContain(baseContext.actionTitle);
+  });
+
+  it('falls back to a generic greeting when firstName is missing', () => {
+    const source = fs.readFileSync(
+      path.join(templatesDir, 'activation.hbs'),
+      'utf-8',
+    );
+    const html = Handlebars.compile(source, { strict: true })({
+      ...baseContext,
+      firstName: undefined,
+    });
+
+    expect(html).toContain('Hallo,');
+    expect(html).not.toContain('Hallo Max,');
+  });
+});
+```
+
+- [ ] **Step 2: Test laufen lassen, erwartetes Scheitern bestätigen**
+
+Run: `cd myteamwallet_backend && npx jest mail-templates.spec.ts`
+Expected: FAIL — `partials/layout.hbs` existiert noch nicht (`ENOENT`), bzw. die bestehenden
+`activation.hbs`/`reset-password.hbs` enthalten weder „TeamWallet" noch „Hallo Max,".
+
+- [ ] **Step 3: Layout-Partial erstellen**
+
+Datei `myteamwallet_backend/src/mail/mail-templates/partials/layout.hbs`:
+
+```handlebars
+<!DOCTYPE html>
+<html lang="de">
+<head>
+<meta charset="UTF-8">
+<meta name="viewport" content="width=device-width, initial-scale=1.0">
+<title>{{title}}</title>
+<style>
+  body { margin: 0; padding: 0; background: #f4f6f4; font-family: Roboto, Helvetica, Arial, sans-serif; }
+  .tw-container { max-width: 600px; margin: 0 auto; padding: 32px 16px; }
+  .tw-card { background: #ffffff; border-radius: 12px; overflow: hidden; box-shadow: 0 1px 3px rgba(15, 23, 42, 0.08); }
+  .tw-header { background: #2e7d32; padding: 28px 32px; text-align: center; }
+  .tw-wordmark { color: #ffffff; font-size: 22px; font-weight: 700; letter-spacing: 0.5px; }
+  .tw-body { padding: 32px; color: #20251f; font-size: 15px; line-height: 1.6; }
+  .tw-body p { margin: 0 0 16px; }
+  .tw-button-row { text-align: center; padding: 8px 0 24px; }
+  .tw-button { display: inline-block; background: #2e7d32; color: #ffffff !important; text-decoration: none; padding: 14px 32px; border-radius: 8px; font-weight: 600; font-size: 15px; }
+  .tw-footer { text-align: center; padding: 20px 16px 0; color: #8a938a; font-size: 12px; line-height: 1.6; }
+  .tw-footer a { color: #8a938a; }
+</style>
+</head>
+<body>
+  <div class="tw-container">
+    <div class="tw-card">
+      <div class="tw-header">
+        <span class="tw-wordmark">TeamWallet</span>
+      </div>
+      <div class="tw-body">
+        {{> @partial-block }}
+      </div>
+    </div>
+    <div class="tw-footer">
+      <p>Diese E-Mail wurde automatisch von TeamWallet verschickt.<br>&copy; {{year}} TeamWallet</p>
+    </div>
+  </div>
+</body>
+</html>
+```
+
+- [ ] **Step 4: `activation.hbs` neu gestalten**
+
+Datei `myteamwallet_backend/src/mail/mail-templates/activation.hbs` komplett ersetzen:
+
+```handlebars
+{{#> layout}}
+<p>Hallo{{#if firstName}} {{firstName}}{{/if}},</p>
+<p>schön, dass du bei TeamWallet dabei bist! Bestätige deine E-Mail-Adresse, um dein Konto zu aktivieren.</p>
+<div class="tw-button-row">
+  <a class="tw-button" href="{{url}}">{{actionTitle}}</a>
+</div>
+<p>Falls der Button nicht funktioniert, kopiere diesen Link in deinen Browser:<br><a href="{{url}}">{{url}}</a></p>
+{{/layout}}
+```
+
+- [ ] **Step 5: `reset-password.hbs` neu gestalten**
+
+Datei `myteamwallet_backend/src/mail/mail-templates/reset-password.hbs` komplett ersetzen:
+
+```handlebars
+{{#> layout}}
+<p>Hallo{{#if firstName}} {{firstName}}{{/if}},</p>
+<p>du hast angefragt, dein TeamWallet-Passwort zurückzusetzen. Klicke auf den Button, um ein neues Passwort zu vergeben.</p>
+<div class="tw-button-row">
+  <a class="tw-button" href="{{url}}">{{actionTitle}}</a>
+</div>
+<p>Falls du diese Anfrage nicht gestellt hast, kannst du diese E-Mail einfach ignorieren — es wird nichts verändert.</p>
+<p>Falls der Button nicht funktioniert, kopiere diesen Link in deinen Browser:<br><a href="{{url}}">{{url}}</a></p>
+{{/layout}}
+```
+
+- [ ] **Step 6: Partials-Verzeichnis in `mail-config.service.ts` registrieren**
+
+In `myteamwallet_backend/src/mail/mail-config.service.ts` den `template.options` Block
+erweitern (`partials.dir` zeigt auf den neuen Ordner, damit `HandlebarsAdapter` die `.hbs`
+Dateien darin beim Versand automatisch als Partials lädt):
+
+```typescript
+  createMailerOptions(): MailerOptions {
+    return {
+      transport: {
+        host: this.configService.get('mail.host'),
+        port: this.configService.get('mail.port'),
+        ignoreTLS: this.configService.get('mail.ignoreTLS'),
+        secure: this.configService.get('mail.secure'),
+        requireTLS: this.configService.get('mail.requireTLS'),
+        auth: {
+          user: this.configService.get('mail.user'),
+          pass: this.configService.get('mail.password'),
+        },
+      },
+      defaults: {
+        from: `"${this.configService.get(
+          'mail.defaultName',
+        )}" <${this.configService.get('mail.defaultEmail')}>`,
+      },
+      template: {
+        dir: path.join(
+          this.configService.get('app.workingDirectory'),
+          'src',
+          'mail',
+          'mail-templates',
+        ),
+        adapter: new HandlebarsAdapter(),
+        options: {
+          strict: true,
+          partials: {
+            dir: path.join(
+              this.configService.get('app.workingDirectory'),
+              'src',
+              'mail',
+              'mail-templates',
+              'partials',
+            ),
+          },
+        },
+      },
+    } as MailerOptions;
+  }
+```
+
+- [ ] **Step 7: Test laufen lassen, Erfolg bestätigen**
+
+Run: `cd myteamwallet_backend && npx jest mail-templates.spec.ts`
+Expected: PASS — alle 3 Tests grün.
+
+- [ ] **Step 8: Alle Unit-Tests + Build**
+
+Run: `cd myteamwallet_backend && npm test && npm run build`
+Expected: alle Tests grün, Build erfolgreich.
+
+- [ ] **Step 9: Commit**
+
+```bash
+git add myteamwallet_backend/src/mail/mail-config.service.ts myteamwallet_backend/src/mail/mail-templates
+git commit -m "feat(mail): redesign email templates with TeamWallet branding and shared layout partial"
+```
+
+---
+
+### Task 4: Manuelle Verifikation mit echtem Versand
+
+Kein Code-Task — Nachweis, dass Registrierung und Passwort-vergessen tatsächlich E-Mails
+verschicken (Strato-SMTP, kein lokaler MailDev vorhanden, siehe Spec).
+
+**Files:** keine.
+
+- [ ] **Step 1: Backend lokal starten**
+
+Voraussetzung: lokale MySQL-Instanz läuft (Container `brave_einstein`, Port 3306, bereits aktiv
+laut `docker ps`), `myteamwallet_backend/.env` unverändert vorhanden.
+
+Run: `cd myteamwallet_backend && npm run start:dev`
+Expected: Server startet ohne Fehler auf Port `3999` (kein Absturz durch die entfernten
+`nestjs-i18n`-Imports, keine `MailerModule`-Config-Fehler).
+
+- [ ] **Step 2: Registrierung auslösen (Aktivierungsmail)**
+
+In einem zweiten Terminal, mit einer echten, von dir kontrollierten Test-Adresse:
+
+```bash
+curl -X POST http://localhost:3999/api/v1/auth/email/register \
+  -H "Content-Type: application/json" \
+  -d '{"email":"DEINE-TEST-ADRESSE@example.com","password":"Test1234!","firstName":"Max","lastName":"Mustermann"}'
+```
+
+Expected: HTTP 201, und innerhalb kurzer Zeit trifft eine E-Mail „Bestätige deine
+E-Mail-Adresse" mit grünem TeamWallet-Header, Begrüßung „Hallo Max," und funktionierendem
+Bestätigungs-Button in der Test-Mailbox ein.
+
+- [ ] **Step 3: Passwort-vergessen auslösen**
+
+```bash
+curl -X POST http://localhost:3999/api/v1/auth/forgot/password \
+  -H "Content-Type: application/json" \
+  -d '{"email":"DEINE-TEST-ADRESSE@example.com"}'
+```
+
+Expected: HTTP 204/200 (je nach Response des Endpoints), und eine E-Mail „Passwort
+zurücksetzen" mit gleichem Layout trifft ein.
+
+- [ ] **Step 4: Server stoppen**
+
+`npm run start:dev` Prozess beenden (Ctrl+C).
+
+- [ ] **Step 5: Ergebnis festhalten**
+
+Kein Commit nötig — dies ist ein manueller Verifikationsschritt. Falls eine der beiden Mails
+nicht ankommt, zurück zu systematic-debugging (SMTP-Verbindung, Firewall, Spam-Ordner prüfen)
+bevor der Task als abgeschlossen gilt.
+
+---
+
+## Self-Review
+
+- **Spec coverage:** Bugfix (Task 1), i18n-Entfernung (Task 2), Template-Redesign inkl.
+  Branding/Partial (Task 3), Personalisierung (Task 1), Testing-Strategie laut korrigiertem Spec
+  — Unit-Tests statt e2e/MailDev (Task 1 + 3), manueller Realversand (Task 4) — alles abgedeckt.
+  `.env` explizit als "keine Aktion" markiert (Global Constraints), passend zum korrigierten
+  Spec.
+- **Placeholder-Scan:** keine TBD/TODO, jeder Step enthält vollständigen Code.
+- **Typ-Konsistenz:** `MailData<{ hash: string; firstName?: string | null }>` konsistent in
+  `mail.service.ts` (Task 1) und den Aufrufstellen in `auth.service.ts` (Task 1) verwendet;
+  Context-Keys `title`/`year`/`firstName`/`url`/`actionTitle` konsistent zwischen `mail.service.ts`
+  (Task 1) und den Templates (Task 3).
diff --git a/env-example b/env-example
index 0d4f88f..b5fd249 100644
--- a/env-example
+++ b/env-example
@@ -2,8 +2,6 @@ NODE_ENV=development
 APP_PORT=3000
 APP_NAME="NestJS API"
 API_PREFIX=api
-APP_FALLBACK_LANGUAGE=en
-APP_HEADER_LANGUAGE=x-custom-lang
 FRONTEND_DOMAIN=http://localhost:3000
 BACKEND_DOMAIN=http://localhost:3000
 
diff --git a/myteamwallet_backend/README.md b/myteamwallet_backend/README.md
index 6979358..d12cc22 100644
--- a/myteamwallet_backend/README.md
+++ b/myteamwallet_backend/README.md
@@ -26,7 +26,6 @@ Seeden: npm run seed:run
 - [x] Sign in and sign up via email.
 - [x] Social sign in (Apple, Facebook, Google, Twitter).
 - [x] Admin and User roles.
-- [x] I18N ([nestjs-i18n](https://www.npmjs.com/package/nestjs-i18n)).
 - [x] File uploads. Support local and Amazon S3 drivers.
 - [x] Swagger.
 - [x] E2E and units tests.
diff --git a/myteamwallet_backend/package-lock.json b/myteamwallet_backend/package-lock.json
index 832e3f6..1055e2a 100644
--- a/myteamwallet_backend/package-lock.json
+++ b/myteamwallet_backend/package-lock.json
@@ -30,7 +30,6 @@
         "multer": "1.4.4",
         "multer-s3": "2.10.0",
         "mysql2": "^2.3.3",
-        "nestjs-i18n": "9.2.2",
         "nodemailer": "6.8.0",
         "passport": "0.6.0",
         "passport-anonymous": "1.0.1",
@@ -4587,11 +4586,6 @@
       "resolved": "https://registry.npmjs.org/abbrev/-/abbrev-1.1.1.tgz",
       "integrity": "sha512-nne9/IiQ/hzIhY6pdDnbBtz7DjPTKrY00P/zvPSm5pOFkl6xuGrGnXn/VtTNNfNtAfZ9/1RtehkszU9qcTii0Q=="
     },
-    "node_modules/accept-language-parser": {
-      "version": "1.5.0",
-      "resolved": "https://registry.npmjs.org/accept-language-parser/-/accept-language-parser-1.5.0.tgz",
-      "integrity": "sha512-QhyTbMLYo0BBGg1aWbeMG4ekWtds/31BrEU+DONOg/7ax23vxpL03Pb7/zBmha2v7vdD3AyzZVWBVGEZxKOXWw=="
-    },
     "node_modules/accepts": {
       "version": "1.3.8",
       "resolved": "https://registry.npmjs.org/accepts/-/accepts-1.3.8.tgz",
@@ -14272,41 +14266,6 @@
       "resolved": "https://registry.npmjs.org/neo-async/-/neo-async-2.6.2.tgz",
       "integrity": "sha512-Yd3UES5mWCSqR+qNT93S3UoYUkqAZ9lLg8a7g9rimsWmYGK8cVToA4/sF3RrshdyV3sAGMXVUmpMYOw+dLpOuw=="
     },
-    "node_modules/nestjs-i18n": {
-      "version": "9.2.2",
-      "resolved": "https://registry.npmjs.org/nestjs-i18n/-/nestjs-i18n-9.2.2.tgz",
-      "integrity": "sha512-GxwDonBnW7MbwuUxF9IHINm0vYhVQUqUnDLxDHPzavs2T2qMDrf/muyqXc9QFIs0v16ElSKz5+aBDZK4nUrgpw==",
-      "dependencies": {
-        "accept-language-parser": "^1.5.0",
-        "chokidar": "^3.5.3",
-        "cookie": "^0.5.0",
-        "iterare": "^1.2.1",
-        "js-yaml": "^4.1.0",
-        "string-format": "^2.0.0"
-      },
-      "peerDependencies": {
-        "@nestjs/common": "*",
-        "@nestjs/core": "*",
-        "class-validator": "~0.13",
-        "rxjs": "*"
-      }
-    },
-    "node_modules/nestjs-i18n/node_modules/argparse": {
-      "version": "2.0.1",
-      "resolved": "https://registry.npmjs.org/argparse/-/argparse-2.0.1.tgz",
-      "integrity": "sha512-8+9WqebbFzpX9OR+Wa6O29asIogeRMzcGtAINdpMHHyAg10f05aSFVBbcEqGf/PXw1EjAZ+q2/bEBg3DvurK3Q=="
-    },
-    "node_modules/nestjs-i18n/node_modules/js-yaml": {
-      "version": "4.1.0",
-      "resolved": "https://registry.npmjs.org/js-yaml/-/js-yaml-4.1.0.tgz",
-      "integrity": "sha512-wpxZs9NoxZaJESJGIZTyDEaYpl0FKSA+FB9aJiyemKhMwkxQg63h4T1KJgUGHpTqPDNRcmmYLugrRjJlBtWvRA==",
-      "dependencies": {
-        "argparse": "^2.0.1"
-      },
-      "bin": {
-        "js-yaml": "bin/js-yaml.js"
-      }
-    },
     "node_modules/netmask": {
       "version": "2.0.2",
       "resolved": "https://registry.npmjs.org/netmask/-/netmask-2.0.2.tgz",
@@ -16339,11 +16298,6 @@
       "resolved": "https://registry.npmjs.org/string_decoder/-/string_decoder-0.10.31.tgz",
       "integrity": "sha1-YuIDvEF2bGwoyfyEMB2rHFMQ+pQ="
     },
-    "node_modules/string-format": {
-      "version": "2.0.0",
-      "resolved": "https://registry.npmjs.org/string-format/-/string-format-2.0.0.tgz",
-      "integrity": "sha512-bbEs3scLeYNXLecRRuk6uJxdXUSj6le/8rNPHChIJTn2V79aXVTR1EH2OH5zLKKoz0V02fOUKZZcw01pLUShZA=="
-    },
     "node_modules/string-length": {
       "version": "4.0.2",
       "resolved": "https://registry.npmjs.org/string-length/-/string-length-4.0.2.tgz",
@@ -21936,11 +21890,6 @@
       "resolved": "https://registry.npmjs.org/abbrev/-/abbrev-1.1.1.tgz",
       "integrity": "sha512-nne9/IiQ/hzIhY6pdDnbBtz7DjPTKrY00P/zvPSm5pOFkl6xuGrGnXn/VtTNNfNtAfZ9/1RtehkszU9qcTii0Q=="
     },
-    "accept-language-parser": {
-      "version": "1.5.0",
-      "resolved": "https://registry.npmjs.org/accept-language-parser/-/accept-language-parser-1.5.0.tgz",
-      "integrity": "sha512-QhyTbMLYo0BBGg1aWbeMG4ekWtds/31BrEU+DONOg/7ax23vxpL03Pb7/zBmha2v7vdD3AyzZVWBVGEZxKOXWw=="
-    },
     "accepts": {
       "version": "1.3.8",
       "resolved": "https://registry.npmjs.org/accepts/-/accepts-1.3.8.tgz",
@@ -29287,34 +29236,6 @@
       "resolved": "https://registry.npmjs.org/neo-async/-/neo-async-2.6.2.tgz",
       "integrity": "sha512-Yd3UES5mWCSqR+qNT93S3UoYUkqAZ9lLg8a7g9rimsWmYGK8cVToA4/sF3RrshdyV3sAGMXVUmpMYOw+dLpOuw=="
     },
-    "nestjs-i18n": {
-      "version": "9.2.2",
-      "resolved": "https://registry.npmjs.org/nestjs-i18n/-/nestjs-i18n-9.2.2.tgz",
-      "integrity": "sha512-GxwDonBnW7MbwuUxF9IHINm0vYhVQUqUnDLxDHPzavs2T2qMDrf/muyqXc9QFIs0v16ElSKz5+aBDZK4nUrgpw==",
-      "requires": {
-        "accept-language-parser": "^1.5.0",
-        "chokidar": "^3.5.3",
-        "cookie": "^0.5.0",
-        "iterare": "^1.2.1",
-        "js-yaml": "^4.1.0",
-        "string-format": "^2.0.0"
-      },
-      "dependencies": {
-        "argparse": {
-          "version": "2.0.1",
-          "resolved": "https://registry.npmjs.org/argparse/-/argparse-2.0.1.tgz",
-          "integrity": "sha512-8+9WqebbFzpX9OR+Wa6O29asIogeRMzcGtAINdpMHHyAg10f05aSFVBbcEqGf/PXw1EjAZ+q2/bEBg3DvurK3Q=="
-        },
-        "js-yaml": {
-          "version": "4.1.0",
-          "resolved": "https://registry.npmjs.org/js-yaml/-/js-yaml-4.1.0.tgz",
-          "integrity": "sha512-wpxZs9NoxZaJESJGIZTyDEaYpl0FKSA+FB9aJiyemKhMwkxQg63h4T1KJgUGHpTqPDNRcmmYLugrRjJlBtWvRA==",
-          "requires": {
-            "argparse": "^2.0.1"
-          }
-        }
-      }
-    },
     "netmask": {
       "version": "2.0.2",
       "resolved": "https://registry.npmjs.org/netmask/-/netmask-2.0.2.tgz",
@@ -30884,11 +30805,6 @@
       "resolved": "https://registry.npmjs.org/string_decoder/-/string_decoder-0.10.31.tgz",
       "integrity": "sha1-YuIDvEF2bGwoyfyEMB2rHFMQ+pQ="
     },
-    "string-format": {
-      "version": "2.0.0",
-      "resolved": "https://registry.npmjs.org/string-format/-/string-format-2.0.0.tgz",
-      "integrity": "sha512-bbEs3scLeYNXLecRRuk6uJxdXUSj6le/8rNPHChIJTn2V79aXVTR1EH2OH5zLKKoz0V02fOUKZZcw01pLUShZA=="
-    },
     "string-length": {
       "version": "4.0.2",
       "resolved": "https://registry.npmjs.org/string-length/-/string-length-4.0.2.tgz",
diff --git a/myteamwallet_backend/package.json b/myteamwallet_backend/package.json
index 67dbc89..c7bb6cf 100644
--- a/myteamwallet_backend/package.json
+++ b/myteamwallet_backend/package.json
@@ -49,7 +49,6 @@
     "multer": "1.4.4",
     "multer-s3": "2.10.0",
     "mysql2": "^2.3.3",
-    "nestjs-i18n": "9.2.2",
     "nodemailer": "6.8.0",
     "passport": "0.6.0",
     "passport-anonymous": "1.0.1",
diff --git a/myteamwallet_backend/src/app.module.ts b/myteamwallet_backend/src/app.module.ts
index 056bed1..53cdcdd 100644
--- a/myteamwallet_backend/src/app.module.ts
+++ b/myteamwallet_backend/src/app.module.ts
@@ -6,12 +6,9 @@ import authConfig from './config/auth.config';
 import appConfig from './config/app.config';
 import mailConfig from './config/mail.config';
 import fileConfig from './config/file.config';
-import * as path from 'path';
 import { MailerModule } from '@nestjs-modules/mailer';
-import { ConfigModule, ConfigService } from '@nestjs/config';
+import { ConfigModule } from '@nestjs/config';
 import { TypeOrmModule } from '@nestjs/typeorm';
-import { I18nModule } from 'nestjs-i18n/dist/i18n.module';
-import { HeaderResolver } from 'nestjs-i18n';
 import { TypeOrmConfigService } from './database/typeorm-config.service';
 import { MailConfigService } from './mail/mail-config.service';
 import { ForgotModule } from './forgot/forgot.module';
@@ -45,23 +42,6 @@ import { PenaltyModule } from './penalty/penalty.module';
     MailerModule.forRootAsync({
       useClass: MailConfigService,
     }),
-    I18nModule.forRootAsync({
-      useFactory: (configService: ConfigService) => ({
-        fallbackLanguage: configService.get('app.fallbackLanguage'),
-        loaderOptions: { path: path.join(__dirname, '/i18n/'), watch: true },
-      }),
-      resolvers: [
-        {
-          use: HeaderResolver,
-          useFactory: (configService: ConfigService) => {
-            return [configService.get('app.headerLanguage')];
-          },
-          inject: [ConfigService],
-        },
-      ],
-      imports: [ConfigModule],
-      inject: [ConfigService],
-    }),
     ServeStaticModule.forRoot({
       rootPath: join(__dirname, '../client'),
       exclude: ['*/api*'],
diff --git a/myteamwallet_backend/src/auth/auth.service.ts b/myteamwallet_backend/src/auth/auth.service.ts
index 4a7ccec..6884669 100644
--- a/myteamwallet_backend/src/auth/auth.service.ts
+++ b/myteamwallet_backend/src/auth/auth.service.ts
@@ -192,6 +192,7 @@ export class AuthService {
       to: user.email,
       data: {
         hash,
+        firstName: user.firstName,
       },
     });
   }
@@ -247,6 +248,7 @@ export class AuthService {
         to: email,
         data: {
           hash,
+          firstName: user.firstName,
         },
       });
     }
diff --git a/myteamwallet_backend/src/config/app.config.ts b/myteamwallet_backend/src/config/app.config.ts
index a33cba4..b02abf3 100644
--- a/myteamwallet_backend/src/config/app.config.ts
+++ b/myteamwallet_backend/src/config/app.config.ts
@@ -8,6 +8,4 @@ export default registerAs('app', () => ({
   backendDomain: process.env.BACKEND_DOMAIN,
   port: parseInt(process.env.APP_PORT || process.env.PORT, 10) || 3000,
   apiPrefix: process.env.API_PREFIX || 'api',
-  fallbackLanguage: process.env.APP_FALLBACK_LANGUAGE || 'en',
-  headerLanguage: process.env.APP_HEADER_LANGUAGE || 'x-custom-lang',
 }));
diff --git a/myteamwallet_backend/src/i18n/en/common.json b/myteamwallet_backend/src/i18n/en/common.json
deleted file mode 100644
index b7a2419..0000000
--- a/myteamwallet_backend/src/i18n/en/common.json
+++ /dev/null
@@ -1,4 +0,0 @@
-{
-  "confirmEmail": "Confirm email",
-  "resetPassword": "Reset password"
-}
diff --git a/myteamwallet_backend/src/i18n/en/confirm-email.json b/myteamwallet_backend/src/i18n/en/confirm-email.json
deleted file mode 100644
index 0eb981d..0000000
--- a/myteamwallet_backend/src/i18n/en/confirm-email.json
+++ /dev/null
@@ -1,5 +0,0 @@
-{
-  "text1": "Hey!",
-  "text2": "You’re almost ready to start enjoying",
-  "text3": "Simply click the big green button below to verify your email address."
-}
diff --git a/myteamwallet_backend/src/i18n/en/reset-password.json b/myteamwallet_backend/src/i18n/en/reset-password.json
deleted file mode 100644
index 6cae96a..0000000
--- a/myteamwallet_backend/src/i18n/en/reset-password.json
+++ /dev/null
@@ -1,6 +0,0 @@
-{
-  "text1": "Trouble signing in?",
-  "text2": "Resetting your password is easy.",
-  "text3": "Just press the button below and follow the instructions. We’ll have you up and running in no time.",
-  "text4": "If you did not make this request then please ignore this email."
-}
diff --git a/myteamwallet_backend/src/mail/mail-config.service.spec.ts b/myteamwallet_backend/src/mail/mail-config.service.spec.ts
new file mode 100644
index 0000000..e8fc09b
--- /dev/null
+++ b/myteamwallet_backend/src/mail/mail-config.service.spec.ts
@@ -0,0 +1,56 @@
+import * as path from 'path';
+import { ConfigService } from '@nestjs/config';
+import { MailConfigService } from './mail-config.service';
+
+describe('MailConfigService integration', () => {
+  it('produces mailer options whose adapter actually renders the shared layout partial', (done) => {
+    const workingDirectory = path.join(__dirname, '..', '..');
+    const configValues: Record<string, unknown> = {
+      'app.workingDirectory': workingDirectory,
+      'mail.host': 'localhost',
+      'mail.port': 1025,
+      'mail.ignoreTLS': true,
+      'mail.secure': false,
+      'mail.requireTLS': false,
+      'mail.user': '',
+      'mail.password': '',
+      'mail.defaultName': 'TeamWallet',
+      'mail.defaultEmail': 'test@example.com',
+    };
+    const configService = {
+      get: (key: string) => configValues[key],
+    } as unknown as ConfigService;
+
+    const options = new MailConfigService(configService).createMailerOptions();
+
+    const mail: {
+      data: {
+        template: string;
+        context: Record<string, unknown>;
+        html?: string;
+      };
+    } = {
+      data: {
+        template: 'activation',
+        context: {
+          title: 'Test',
+          year: 2026,
+          firstName: 'Max',
+          url: 'https://example.com/confirm-email/abc',
+          actionTitle: 'Jetzt bestätigen',
+        },
+      },
+    };
+
+    options.template.adapter.compile(
+      mail,
+      (err?: Error) => {
+        expect(err).toBeUndefined();
+        expect(mail.data.html).toContain('TeamWallet');
+        expect(mail.data.html).toContain('tw-wordmark');
+        done();
+      },
+      options,
+    );
+  });
+});
diff --git a/myteamwallet_backend/src/mail/mail-config.service.ts b/myteamwallet_backend/src/mail/mail-config.service.ts
index 4a6cba6..acec8db 100644
--- a/myteamwallet_backend/src/mail/mail-config.service.ts
+++ b/myteamwallet_backend/src/mail/mail-config.service.ts
@@ -1,4 +1,6 @@
 import * as path from 'path';
+import * as fs from 'fs';
+import * as handlebars from 'handlebars';
 import { Injectable } from '@nestjs/common';
 import { ConfigService } from '@nestjs/config';
 import { MailerOptions, MailerOptionsFactory } from '@nestjs-modules/mailer';
@@ -9,6 +11,21 @@ export class MailConfigService implements MailerOptionsFactory {
   constructor(private configService: ConfigService) {}
 
   createMailerOptions(): MailerOptions {
+    const templatesDir = path.join(
+      this.configService.get('app.workingDirectory'),
+      'src',
+      'mail',
+      'mail-templates',
+    );
+
+    handlebars.registerPartial(
+      'layout',
+      fs.readFileSync(
+        path.join(templatesDir, 'partials', 'layout.hbs'),
+        'utf-8',
+      ),
+    );
+
     return {
       transport: {
         host: this.configService.get('mail.host'),
@@ -27,12 +44,7 @@ export class MailConfigService implements MailerOptionsFactory {
         )}" <${this.configService.get('mail.defaultEmail')}>`,
       },
       template: {
-        dir: path.join(
-          this.configService.get('app.workingDirectory'),
-          'src',
-          'mail',
-          'mail-templates',
-        ),
+        dir: templatesDir,
         adapter: new HandlebarsAdapter(),
         options: {
           strict: true,
diff --git a/myteamwallet_backend/src/mail/mail-templates/activation.hbs b/myteamwallet_backend/src/mail/mail-templates/activation.hbs
index edee05e..62850ab 100644
--- a/myteamwallet_backend/src/mail/mail-templates/activation.hbs
+++ b/myteamwallet_backend/src/mail/mail-templates/activation.hbs
@@ -1,33 +1,8 @@
-<!DOCTYPE html>
-<html lang="en">
-
-<head>
-    <meta charset="UTF-8">
-    <meta name="viewport" content="width=device-width, initial-scale=">
-    <title>{{title}}</title>
-</head>
-
-<body style="margin:0;font-family:arial">
-    <table style="border:0;width:100%">
-        <tr style="background:#eeeeee">
-            <td style="padding:20px;color:#808080;text-align:center;font-size:40px;font-weight:600">
-                {{app_name}}
-            </td>
-        </tr>
-        <tr>
-            <td style="padding:20px;color:#808080;font-size:16px;font-weight:100">
-                {{text1}}<br>
-                {{text2}} {{app_name}}.<br>
-                {{text3}}
-            </td>
-        </tr>
-        <tr>
-            <td style="text-align:center">
-                <a href="{{url}}"
-                    style="display:inline-block;padding:20px;background:#00838f;text-decoration:none;color:#ffffff">{{actionTitle}}</a>
-            </td>
-        </tr>
-    </table>
-</body>
-
-</html>
\ No newline at end of file
+{{#> layout}}
+<p>Hallo{{#if firstName}} {{firstName}}{{/if}},</p>
+<p>schön, dass du bei TeamWallet dabei bist! Bestätige deine E-Mail-Adresse, um dein Konto zu aktivieren.</p>
+<div class="tw-button-row">
+  <a class="tw-button" href="{{url}}">{{actionTitle}}</a>
+</div>
+<p>Falls der Button nicht funktioniert, kopiere diesen Link in deinen Browser:<br><a href="{{url}}">{{url}}</a></p>
+{{/layout}}
diff --git a/myteamwallet_backend/src/mail/mail-templates/mail-templates.spec.ts b/myteamwallet_backend/src/mail/mail-templates/mail-templates.spec.ts
new file mode 100644
index 0000000..0caa9e1
--- /dev/null
+++ b/myteamwallet_backend/src/mail/mail-templates/mail-templates.spec.ts
@@ -0,0 +1,63 @@
+import * as fs from 'fs';
+import * as path from 'path';
+import * as Handlebars from 'handlebars';
+
+describe('mail templates rendering', () => {
+  const templatesDir = __dirname;
+
+  beforeAll(() => {
+    const layoutSource = fs.readFileSync(
+      path.join(templatesDir, 'partials', 'layout.hbs'),
+      'utf-8',
+    );
+    Handlebars.registerPartial('layout', layoutSource);
+  });
+
+  const baseContext = {
+    title: 'Test-Betreff',
+    year: 2026,
+    firstName: 'Max',
+    url: 'https://app.example.com/confirm-email/abc123',
+    actionTitle: 'Jetzt bestätigen',
+  };
+
+  it('renders activation.hbs with greeting, link and button text', () => {
+    const source = fs.readFileSync(
+      path.join(templatesDir, 'activation.hbs'),
+      'utf-8',
+    );
+    const html = Handlebars.compile(source, { strict: true })(baseContext);
+
+    expect(html).toContain('TeamWallet');
+    expect(html).toContain('Hallo Max,');
+    expect(html).toContain(baseContext.url);
+    expect(html).toContain(baseContext.actionTitle);
+  });
+
+  it('renders reset-password.hbs with greeting, link and button text', () => {
+    const source = fs.readFileSync(
+      path.join(templatesDir, 'reset-password.hbs'),
+      'utf-8',
+    );
+    const html = Handlebars.compile(source, { strict: true })(baseContext);
+
+    expect(html).toContain('TeamWallet');
+    expect(html).toContain('Hallo Max,');
+    expect(html).toContain(baseContext.url);
+    expect(html).toContain(baseContext.actionTitle);
+  });
+
+  it('falls back to a generic greeting when firstName is missing', () => {
+    const source = fs.readFileSync(
+      path.join(templatesDir, 'activation.hbs'),
+      'utf-8',
+    );
+    const html = Handlebars.compile(source, { strict: true })({
+      ...baseContext,
+      firstName: undefined,
+    });
+
+    expect(html).toContain('Hallo,');
+    expect(html).not.toContain('Hallo Max,');
+  });
+});
diff --git a/myteamwallet_backend/src/mail/mail-templates/partials/layout.hbs b/myteamwallet_backend/src/mail/mail-templates/partials/layout.hbs
new file mode 100644
index 0000000..723775e
--- /dev/null
+++ b/myteamwallet_backend/src/mail/mail-templates/partials/layout.hbs
@@ -0,0 +1,36 @@
+<!DOCTYPE html>
+<html lang="de">
+<head>
+<meta charset="UTF-8">
+<meta name="viewport" content="width=device-width, initial-scale=1.0">
+<title>{{title}}</title>
+<style>
+  body { margin: 0; padding: 0; background: #f4f6f4; font-family: Roboto, Helvetica, Arial, sans-serif; }
+  .tw-container { max-width: 600px; margin: 0 auto; padding: 32px 16px; }
+  .tw-card { background: #ffffff; border-radius: 12px; overflow: hidden; box-shadow: 0 1px 3px rgba(15, 23, 42, 0.08); }
+  .tw-header { background: #2e7d32; padding: 28px 32px; text-align: center; }
+  .tw-wordmark { color: #ffffff; font-size: 22px; font-weight: 700; letter-spacing: 0.5px; }
+  .tw-body { padding: 32px; color: #20251f; font-size: 15px; line-height: 1.6; }
+  .tw-body p { margin: 0 0 16px; }
+  .tw-button-row { text-align: center; padding: 8px 0 24px; }
+  .tw-button { display: inline-block; background: #2e7d32; color: #ffffff !important; text-decoration: none; padding: 14px 32px; border-radius: 8px; font-weight: 600; font-size: 15px; }
+  .tw-footer { text-align: center; padding: 20px 16px 0; color: #8a938a; font-size: 12px; line-height: 1.6; }
+  .tw-footer a { color: #8a938a; }
+</style>
+</head>
+<body>
+  <div class="tw-container">
+    <div class="tw-card">
+      <div class="tw-header">
+        <span class="tw-wordmark">TeamWallet</span>
+      </div>
+      <div class="tw-body">
+        {{> @partial-block }}
+      </div>
+    </div>
+    <div class="tw-footer">
+      <p>Diese E-Mail wurde automatisch von TeamWallet verschickt.<br>&copy; {{year}} TeamWallet</p>
+    </div>
+  </div>
+</body>
+</html>
diff --git a/myteamwallet_backend/src/mail/mail-templates/reset-password.hbs b/myteamwallet_backend/src/mail/mail-templates/reset-password.hbs
index 3c0e405..ae32299 100644
--- a/myteamwallet_backend/src/mail/mail-templates/reset-password.hbs
+++ b/myteamwallet_backend/src/mail/mail-templates/reset-password.hbs
@@ -1,38 +1,9 @@
-<!DOCTYPE html>
-<html lang="en">
-
-<head>
-    <meta charset="UTF-8">
-    <meta name="viewport" content="width=device-width, initial-scale=">
-    <title>{{title}}</title>
-</head>
-
-<body style="margin:0;font-family:arial">
-    <table style="border:0;width:100%">
-        <tr style="background:#eeeeee">
-            <td style="padding:20px;color:#808080;text-align:center;font-size:40px;font-weight:600">
-                {{app_name}}
-            </td>
-        </tr>
-        <tr>
-            <td style="padding:20px;color:#808080;font-size:16px;font-weight:100">
-                {{text1}}<br>
-                {{text2}}<br>
-                {{text3}}
-            </td>
-        </tr>
-        <tr>
-            <td style="text-align:center">
-                <a href="{{url}}"
-                    style="display:inline-block;padding:20px;background:#00838f;text-decoration:none;color:#ffffff">{{actionTitle}}</a>
-            </td>
-        </tr>
-        <tr>
-            <td style="padding:20px;color:#808080;font-size:16px;font-weight:100">
-                {{text4}}
-            </td>
-        </tr>
-    </table>
-</body>
-
-</html>
\ No newline at end of file
+{{#> layout}}
+<p>Hallo{{#if firstName}} {{firstName}}{{/if}},</p>
+<p>du hast angefragt, dein TeamWallet-Passwort zurückzusetzen. Klicke auf den Button, um ein neues Passwort zu vergeben.</p>
+<div class="tw-button-row">
+  <a class="tw-button" href="{{url}}">{{actionTitle}}</a>
+</div>
+<p>Falls du diese Anfrage nicht gestellt hast, kannst du diese E-Mail einfach ignorieren — es wird nichts verändert.</p>
+<p>Falls der Button nicht funktioniert, kopiere diesen Link in deinen Browser:<br><a href="{{url}}">{{url}}</a></p>
+{{/layout}}
diff --git a/myteamwallet_backend/src/mail/mail.service.spec.ts b/myteamwallet_backend/src/mail/mail.service.spec.ts
new file mode 100644
index 0000000..9e33ddc
--- /dev/null
+++ b/myteamwallet_backend/src/mail/mail.service.spec.ts
@@ -0,0 +1,61 @@
+import { ConfigService } from '@nestjs/config';
+import { MailerService } from '@nestjs-modules/mailer';
+import { MailService } from './mail.service';
+
+describe('MailService', () => {
+  let service: MailService;
+  let sendMail: jest.Mock;
+  let configGet: jest.Mock;
+
+  beforeEach(() => {
+    sendMail = jest.fn().mockResolvedValue(undefined);
+    configGet = jest.fn().mockReturnValue('https://app.example.com');
+
+    service = new MailService(
+      { sendMail } as unknown as MailerService,
+      { get: configGet } as unknown as ConfigService,
+    );
+  });
+
+  it('sends the activation mail with the confirm-email link', async () => {
+    await service.userSignUp({
+      to: 'user@example.com',
+      data: { hash: 'abc123', firstName: 'Max' },
+    });
+
+    expect(sendMail).toHaveBeenCalledTimes(1);
+    const call = sendMail.mock.calls[0][0];
+    expect(call.to).toBe('user@example.com');
+    expect(call.template).toBe('activation');
+    expect(call.context.url).toBe(
+      'https://app.example.com/confirm-email/abc123',
+    );
+    expect(call.context.firstName).toBe('Max');
+  });
+
+  it('sends the reset-password mail with the password-change link', async () => {
+    await service.forgotPassword({
+      to: 'user@example.com',
+      data: { hash: 'xyz789', firstName: 'Erika' },
+    });
+
+    expect(sendMail).toHaveBeenCalledTimes(1);
+    const call = sendMail.mock.calls[0][0];
+    expect(call.to).toBe('user@example.com');
+    expect(call.template).toBe('reset-password');
+    expect(call.context.url).toBe(
+      'https://app.example.com/password-change/xyz789',
+    );
+    expect(call.context.firstName).toBe('Erika');
+  });
+
+  it('works without a firstName (optional personalization)', async () => {
+    await service.userSignUp({
+      to: 'user@example.com',
+      data: { hash: 'abc123' },
+    });
+
+    const call = sendMail.mock.calls[0][0];
+    expect(call.context.firstName).toBeUndefined();
+  });
+});
diff --git a/myteamwallet_backend/src/mail/mail.service.ts b/myteamwallet_backend/src/mail/mail.service.ts
index 94ce813..a825da8 100644
--- a/myteamwallet_backend/src/mail/mail.service.ts
+++ b/myteamwallet_backend/src/mail/mail.service.ts
@@ -1,61 +1,57 @@
 import { MailerService } from '@nestjs-modules/mailer';
 import { Injectable } from '@nestjs/common';
 import { ConfigService } from '@nestjs/config';
-import { I18n, I18nRequestScopeService } from 'nestjs-i18n';
 import { MailData } from './interfaces/mail-data.interface';
 
 @Injectable()
 export class MailService {
   constructor(
-    @I18n()
-    private i18n: I18nRequestScopeService,
     private mailerService: MailerService,
     private configService: ConfigService,
   ) {}
 
-  async userSignUp(mailData: MailData<{ hash: string }>) {
-    return;
+  async userSignUp(
+    mailData: MailData<{ hash: string; firstName?: string | null }>,
+  ) {
+    const actionTitle = 'E-Mail bestätigen';
+    const url = `${this.configService.get('app.frontendDomain')}/confirm-email/${
+      mailData.data.hash
+    }`;
+
     await this.mailerService.sendMail({
       to: mailData.to,
-      subject: await this.i18n.t('common.confirmEmail'),
-      text: `${this.configService.get('app.frontendDomain')}/confirm-email/${
-        mailData.data.hash
-      } ${await this.i18n.t('common.confirmEmail')}`,
+      subject: 'Bestätige deine E-Mail-Adresse',
+      text: `${url} ${actionTitle}`,
       template: 'activation',
       context: {
-        title: await this.i18n.t('common.confirmEmail'),
-        url: `${this.configService.get('app.frontendDomain')}/confirm-email/${
-          mailData.data.hash
-        }`,
-        actionTitle: await this.i18n.t('common.confirmEmail'),
-        app_name: this.configService.get('app.name'),
-        text1: await this.i18n.t('confirm-email.text1'),
-        text2: await this.i18n.t('confirm-email.text2'),
-        text3: await this.i18n.t('confirm-email.text3'),
+        title: 'Bestätige deine E-Mail-Adresse',
+        year: new Date().getFullYear(),
+        firstName: mailData.data.firstName,
+        url,
+        actionTitle,
       },
     });
   }
 
-  async forgotPassword(mailData: MailData<{ hash: string }>) {
-    return;
+  async forgotPassword(
+    mailData: MailData<{ hash: string; firstName?: string | null }>,
+  ) {
+    const actionTitle = 'Passwort zurücksetzen';
+    const url = `${this.configService.get('app.frontendDomain')}/password-change/${
+      mailData.data.hash
+    }`;
+
     await this.mailerService.sendMail({
       to: mailData.to,
-      subject: await this.i18n.t('common.resetPassword'),
-      text: `${this.configService.get('app.frontendDomain')}/password-change/${
-        mailData.data.hash
-      } ${await this.i18n.t('common.resetPassword')}`,
+      subject: actionTitle,
+      text: `${url} ${actionTitle}`,
       template: 'reset-password',
       context: {
-        title: await this.i18n.t('common.resetPassword'),
-        url: `${this.configService.get('app.frontendDomain')}/password-change/${
-          mailData.data.hash
-        }`,
-        actionTitle: await this.i18n.t('common.resetPassword'),
-        app_name: this.configService.get('app.name'),
-        text1: await this.i18n.t('reset-password.text1'),
-        text2: await this.i18n.t('reset-password.text2'),
-        text3: await this.i18n.t('reset-password.text3'),
-        text4: await this.i18n.t('reset-password.text4'),
+        title: actionTitle,
+        year: new Date().getFullYear(),
+        firstName: mailData.data.firstName,
+        url,
+        actionTitle,
       },
     });
   }