From b6e40b9a2ac48571fcb11a9a0688f61cecec56f4 Mon Sep 17 00:00:00 2001
From: Paul Nothaft <53005142+the-luap@users.noreply.github.com>
Date: Fri, 4 Sep 2026 14:24:02 +0200
Subject: [PATCH] feat(email): global signature footer from the business
 profile (#1264)
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

The business profile already carried the operator's full issuer block —
address, phone, email, website, VAT id — but none of it reached an email.
Those columns only fed the quote/invoice PDF renderer, so every outgoing
mail footer was the fixed logo + company name + copyright line.

The signature is rendered by wrapEmailHtml and nowhere else, so no
template, no per-type send path and no queue row needed a change. Two new
columns on business_profile (migration 198) carry the toggle and one
free-text legal line; everything else is read from the address fields the
operator already maintains.

Default off, with a test pinning that the disabled path is byte-identical
to a no-profile install.

Includes three rounds of external review fixes: the plain-text MIME part
also carries the signature; string booleans ('false'/'0') no longer
invert the toggle; the status line stays silent rather than asserting
"off" while unauthorised or loading; and the preview's Text tab mirrors
the send path's htmlToText fallback.

Manual Messages replies deliberately keep no signature — they bypass the
wrapper by design — and the UI copy names that exception.

Closes #1264 (Part A)
---
 .../businessProfileSignature.test.js          | 144 +++++++++
 .../integration/emailSignatureFooter.test.js  | 276 ++++++++++++++++++
 .../198_business_profile_email_signature.js   |  46 +++
 backend/src/routes/adminBusinessProfile.js    |  14 +
 backend/src/routes/adminEmail.js              |  26 +-
 .../src/services/businessProfileService.js    | 120 +++++++-
 backend/src/services/emailProcessor.js        | 175 ++++++++++-
 backend/src/services/guestRecoveryService.js  |   5 +-
 frontend/src/i18n/locales/de.json             |  19 +-
 frontend/src/i18n/locales/en.json             |  19 +-
 frontend/src/pages/admin/EmailConfigPage.tsx  |  41 +++
 .../settings/SettingsBusinessProfilePage.tsx  | 112 ++++++-
 .../__tests__/emailSignatureCard.test.tsx     | 164 +++++++++++
 .../src/services/businessProfile.service.ts   |  10 +
 14 files changed, 1155 insertions(+), 16 deletions(-)
 create mode 100644 backend/__tests__/integration/businessProfileSignature.test.js
 create mode 100644 backend/__tests__/integration/emailSignatureFooter.test.js
 create mode 100644 backend/migrations/core/198_business_profile_email_signature.js
 create mode 100644 frontend/src/pages/admin/settings/__tests__/emailSignatureCard.test.tsx

diff --git a/backend/__tests__/integration/businessProfileSignature.test.js b/backend/__tests__/integration/businessProfileSignature.test.js
new file mode 100644
index 00000000..9a7a3c19
--- /dev/null
+++ b/backend/__tests__/integration/businessProfileSignature.test.js
@@ -0,0 +1,144 @@
+/**
+ * PUT /api/admin/business-profile — email signature fields (migration 198).
+ *
+ * The two new columns are boolean + free text, which is exactly the shape
+ * that goes wrong quietly: `optional({ values: 'falsy' })` on the boolean
+ * would silently drop `false`, leaving the admin unable to switch the
+ * signature back off. The round-trip below is what pins that.
+ */
+
+const path = require('path');
+const fs = require('fs');
+const os = require('os');
+
+const tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'picpeak-bpsig-test-'));
+process.env.NODE_ENV = 'test';
+process.env.TEST_DATABASE_PATH = path.join(tmpDir, 'db.sqlite');
+process.env.STORAGE_PATH = path.join(tmpDir, 'storage');
+fs.mkdirSync(process.env.STORAGE_PATH, { recursive: true });
+process.env.JWT_SECRET = process.env.JWT_SECRET || 'bpsig-route-test-secret';
+
+const request = require('supertest');
+const {
+  bootCrmDb, seedMinimal, assignAdminRole, mintAdminToken, buildRouteApp,
+} = require('./helpers/crmDb');
+
+describe('business profile — email signature round-trip', () => {
+  let db;
+  let cleanup;
+  let app;
+  let token;
+
+  const put = (payload) => request(app)
+    .put('/api/admin/business-profile')
+    .set('Authorization', `Bearer ${token}`)
+    .send(payload);
+
+  const get = () => request(app)
+    .get('/api/admin/business-profile')
+    .set('Authorization', `Bearer ${token}`);
+
+  // GET returns the snapshot at the top level; PUT wraps it in
+  // successResponse's `data` envelope. Read either.
+  const profileOf = (res) => (res.body.data || res.body).profile;
+
+  beforeAll(async () => {
+    ({ db, cleanup } = await bootCrmDb());
+    const { adminId } = await seedMinimal(db);
+    await assignAdminRole(db, adminId, 'super_admin');
+    token = mintAdminToken(adminId);
+    app = buildRouteApp('/api/admin/business-profile', require('../../src/routes/adminBusinessProfile'));
+  }, 120000);
+
+  afterAll(async () => {
+    if (cleanup) await cleanup();
+  });
+
+  it('defaults to off with an empty legal line', async () => {
+    const res = await get();
+    expect(res.status).toBe(200);
+    const profile = profileOf(res);
+    expect(profile.emailSignatureEnabled).toBe(false);
+    expect(profile.emailSignatureExtra).toBe('');
+  });
+
+  it('persists the toggle and the legal line', async () => {
+    const res = await put({
+      emailSignatureEnabled: true,
+      emailSignatureExtra: 'Handelsregister Vaduz FL-0002.123.456-7',
+    });
+    expect(res.status).toBe(200);
+
+    const profile = profileOf(await get());
+    expect(profile.emailSignatureEnabled).toBe(true);
+    expect(profile.emailSignatureExtra).toBe('Handelsregister Vaduz FL-0002.123.456-7');
+  });
+
+  it('switches the toggle back off — `false` is not dropped as falsy', async () => {
+    await put({ emailSignatureEnabled: true });
+    const res = await put({ emailSignatureEnabled: false });
+    expect(res.status).toBe(200);
+
+    expect(profileOf(await get()).emailSignatureEnabled).toBe(false);
+  });
+
+  it('clears the legal line with an empty string', async () => {
+    await put({ emailSignatureExtra: 'something' });
+    const res = await put({ emailSignatureExtra: '' });
+    expect(res.status).toBe(200);
+
+    expect(profileOf(await get()).emailSignatureExtra).toBe('');
+  });
+
+  it('trims surrounding whitespace off the legal line', async () => {
+    await put({ emailSignatureExtra: '  Registered in Vaduz  ' });
+    expect(profileOf(await get()).emailSignatureExtra).toBe('Registered in Vaduz');
+  });
+
+  // Codex review: express-validator's isBoolean() accepts the STRINGS
+  // 'false' and '0', and Boolean('false') is true — so a form-encoded client
+  // trying to switch the signature OFF switched it on instead.
+  it.each([['false'], ['0']])('treats the string %s as off, not on', async (value) => {
+    await put({ emailSignatureEnabled: true });
+    expect(profileOf(await get()).emailSignatureEnabled).toBe(true);
+
+    const res = await put({ emailSignatureEnabled: value });
+    expect(res.status).toBe(200);
+    expect(profileOf(await get()).emailSignatureEnabled).toBe(false);
+  });
+
+  it.each([['true'], ['1']])('treats the string %s as on', async (value) => {
+    await put({ emailSignatureEnabled: false });
+    const res = await put({ emailSignatureEnabled: value });
+    expect(res.status).toBe(200);
+    expect(profileOf(await get()).emailSignatureEnabled).toBe(true);
+  });
+
+  it('rejects a non-boolean toggle and a legal line over 500 chars', async () => {
+    expect((await put({ emailSignatureEnabled: 'yes please' })).status).toBe(400);
+    expect((await put({ emailSignatureExtra: 'x'.repeat(501) })).status).toBe(400);
+  });
+
+  it('does not let an unmapped column ride in on the payload', async () => {
+    // ALLOWED_PROFILE_FIELDS is the whitelist; the route's camel→snake map
+    // is the second gate. Neither should pass a raw snake_case key through.
+    const before = await db('business_profile').where({ id: 1 }).first();
+    await put({ email_signature_enabled: true, id: 999 });
+    const after = await db('business_profile').where({ id: 1 }).first();
+
+    expect(after.id).toBe(before.id);
+    expect(after.email_signature_enabled).toBe(before.email_signature_enabled);
+  });
+
+  it('invalidates the wrapper signature cache on write', async () => {
+    const { wrapEmailHtml } = require('../../src/services/emailProcessor');
+
+    await put({ emailSignatureEnabled: false });
+    expect(await wrapEmailHtml('<p>x</p>', 'S')).not.toContain('Bahnhofstrasse 9');
+
+    // Same request cycle, well inside the 60 s memo window: the PUT must
+    // clear the cache or the operator sees a stale footer for a minute.
+    await put({ emailSignatureEnabled: true, addressLine1: 'Bahnhofstrasse 9' });
+    expect(await wrapEmailHtml('<p>x</p>', 'S')).toContain('Bahnhofstrasse 9');
+  });
+});
diff --git a/backend/__tests__/integration/emailSignatureFooter.test.js b/backend/__tests__/integration/emailSignatureFooter.test.js
new file mode 100644
index 00000000..9b7c8be3
--- /dev/null
+++ b/backend/__tests__/integration/emailSignatureFooter.test.js
@@ -0,0 +1,276 @@
+/**
+ * Global email footer signature (migration 198, issue #1264).
+ *
+ * The signature is rendered by `wrapEmailHtml` and nowhere else, which is
+ * the whole point of the design: every template, preview, test mail and
+ * manual send passes through that one wrapper, so none of them needed a
+ * per-template change. These tests pin that contract at the wrapper.
+ *
+ * The load-bearing case is the DISABLED one — an upgraded install must keep
+ * a byte-identical footer until an admin opts in.
+ */
+
+const { bootCrmDb } = require('./helpers/crmDb');
+
+describe('wrapEmailHtml — business-profile signature footer', () => {
+  let db;
+  let cleanup;
+  let wrapEmailHtml;
+  let renderEmailSignatureText;
+  let businessProfileService;
+
+  beforeAll(async () => {
+    ({ db, cleanup } = await bootCrmDb());
+    ({ wrapEmailHtml, renderEmailSignatureText } = require('../../src/services/emailProcessor'));
+    businessProfileService = require('../../src/services/businessProfileService');
+  }, 120000);
+
+  afterAll(async () => {
+    if (cleanup) await cleanup();
+  });
+
+  beforeEach(async () => {
+    await db('business_profile').where({ id: 1 }).update({
+      company_name: null,
+      address_line1: null,
+      address_line2: null,
+      postal_code: null,
+      city: null,
+      country_code: null,
+      country_name: null,
+      phone: null,
+      mobile: null,
+      email: null,
+      website: null,
+      vat_id: null,
+      email_signature_enabled: false,
+      email_signature_extra: null,
+    });
+    businessProfileService.invalidateEmailSignatureCache();
+  });
+
+  const fullProfile = {
+    company_name: 'Müller Fotografie GmbH',
+    address_line1: 'Bahnhofstrasse 1',
+    address_line2: 'Postfach 42',
+    postal_code: '9494',
+    city: 'Schaan',
+    country_code: 'li',
+    country_name: 'Liechtenstein',
+    phone: '+41 79 123 45 67',
+    mobile: '+41 78 000 11 22',
+    email: 'hello@example.com',
+    website: 'example.com',
+    vat_id: 'CHE-123.456.789',
+    email_signature_enabled: true,
+    email_signature_extra: 'Handelsregister Vaduz\nFL-0002.123.456-7',
+  };
+
+  async function enable(overrides = {}) {
+    await db('business_profile').where({ id: 1 }).update({ ...fullProfile, ...overrides });
+    businessProfileService.invalidateEmailSignatureCache();
+  }
+
+  it('renders nothing extra when the toggle is off', async () => {
+    // Profile fully populated, signature switched OFF: the operator's
+    // address must not leak into mail just because they filled in the
+    // invoice issuer block.
+    await enable({ email_signature_enabled: false });
+
+    const html = await wrapEmailHtml('<p>Body</p>', 'Subject');
+
+    expect(html).not.toContain('Bahnhofstrasse 1');
+    expect(html).not.toContain('hello@example.com');
+    expect(html).not.toContain('CHE-123.456.789');
+  });
+
+  it('produces a byte-identical footer to a no-profile install when disabled', async () => {
+    const withEmptyProfile = await wrapEmailHtml('<p>Body</p>', 'Subject');
+    await enable({ email_signature_enabled: false });
+    const withDisabledSignature = await wrapEmailHtml('<p>Body</p>', 'Subject');
+
+    expect(withDisabledSignature).toBe(withEmptyProfile);
+  });
+
+  it('renders address, contacts, VAT id and the legal line when enabled', async () => {
+    await enable();
+
+    const html = await wrapEmailHtml('<p>Body</p>', 'Subject');
+
+    expect(html).toContain('Müller Fotografie GmbH');
+    expect(html).toContain('Bahnhofstrasse 1');
+    expect(html).toContain('Postfach 42');
+    // "LI-9494 Schaan / Liechtenstein" — same shape as the PDF issuer block.
+    expect(html).toContain('LI-9494 Schaan / Liechtenstein');
+    expect(html).toContain('VAT ID: CHE-123.456.789');
+    expect(html).toContain('Handelsregister Vaduz<br />FL-0002.123.456-7');
+  });
+
+  it('links phone, mobile, email and website with safe schemes', async () => {
+    await enable();
+
+    const html = await wrapEmailHtml('<p>Body</p>', 'Subject');
+
+    // Separators stripped from the tel: href, kept in the visible text.
+    expect(html).toContain('href="tel:+41791234567"');
+    expect(html).toContain('href="tel:+41780001122"');
+    expect(html).toContain('href="mailto:hello@example.com"');
+    // A bare hostname is promoted to https:// rather than left relative.
+    expect(html).toContain('href="https://example.com"');
+  });
+
+  it('keeps an already-absolute website URL as typed', async () => {
+    await enable({ website: 'http://legacy.example.org/studio' });
+
+    const html = await wrapEmailHtml('<p>Body</p>', 'Subject');
+
+    expect(html).toContain('href="http://legacy.example.org/studio"');
+  });
+
+  it('neutralises a javascript: website into an inert https URL', async () => {
+    await enable({ website: 'javascript:alert(1)' });
+
+    const html = await wrapEmailHtml('<p>Body</p>', 'Subject');
+
+    expect(html).not.toContain('href="javascript:');
+    expect(html).toContain('href="https://javascript:alert(1)"');
+  });
+
+  it('HTML-escapes every signature field', async () => {
+    await enable({
+      company_name: '<script>alert(1)</script>',
+      address_line1: 'Rue "des" Fleurs & Co',
+      vat_id: '<img src=x onerror=alert(1)>',
+      email_signature_extra: '</p><script>alert(2)</script>',
+    });
+
+    const html = await wrapEmailHtml('<p>Body</p>', 'Subject');
+
+    // Escaped, so the markup is inert text — the tags never open.
+    expect(html).not.toContain('<script>alert(1)</script>');
+    expect(html).not.toContain('<script>alert(2)</script>');
+    expect(html).not.toContain('<img src=x');
+    expect(html).toContain('&lt;script&gt;alert(1)&lt;/script&gt;');
+    expect(html).toContain('&lt;img src=x onerror=alert(1)&gt;');
+    expect(html).toContain('Rue &quot;des&quot; Fleurs &amp; Co');
+  });
+
+  it('does not repeat the branding company name', async () => {
+    // Footer already prints the branding name; the profile name is only
+    // added when the operator gave a different legal name.
+    await db('app_settings')
+      .insert({ setting_key: 'branding_company_name', setting_value: JSON.stringify('Müller Fotografie GmbH'), setting_type: 'branding' })
+      .onConflict('setting_key')
+      .merge();
+    await enable();
+
+    const html = await wrapEmailHtml('<p>Body</p>', 'Subject');
+
+    expect(html.match(/Müller Fotografie GmbH/g).length).toBe(
+      // header alt, footer alt, footer name line, copyright line — the
+      // signature must not add a fifth.
+      (await wrapEmailHtml('<p>Body</p>', 'Subject', 'en')).match(/Müller Fotografie GmbH/g).length
+    );
+    expect(html.match(/Müller Fotografie GmbH/g).length).toBe(4);
+
+    await db('app_settings').where({ setting_key: 'branding_company_name' }).del();
+  });
+
+  it('uses the German VAT label for a German mail', async () => {
+    await enable();
+
+    const de = await wrapEmailHtml('<p>Body</p>', 'Subject', 'de');
+    const en = await wrapEmailHtml('<p>Body</p>', 'Subject', 'en');
+
+    expect(de).toContain('USt-IdNr.: CHE-123.456.789');
+    expect(en).toContain('VAT ID: CHE-123.456.789');
+  });
+
+  it('omits empty fields instead of rendering blank rows', async () => {
+    await enable({
+      address_line2: null, mobile: null, website: null, vat_id: null, email_signature_extra: null,
+    });
+
+    const html = await wrapEmailHtml('<p>Body</p>', 'Subject');
+
+    expect(html).toContain('hello@example.com');
+    expect(html).not.toContain('VAT ID:');
+    expect(html).not.toMatch(/&middot;\s*&middot;/);
+  });
+
+  it('renders no signature block when enabled but the profile is blank', async () => {
+    await db('business_profile').where({ id: 1 }).update({ email_signature_enabled: true });
+    businessProfileService.invalidateEmailSignatureCache();
+
+    const html = await wrapEmailHtml('<p>Body</p>', 'Subject');
+
+    // The signature <div> is the only element carrying this margin.
+    expect(html).not.toContain('<div style="margin:15px 0 5px;');
+  });
+
+  // Codex review: sendTemplateEmail uses a template's own body_text when it
+  // has one — every seeded template does — so the text/plain alternative is
+  // NOT derived from the wrapped HTML and carried no signature at all.
+  describe('plain-text alternative', () => {
+    it('renders the signature as plain text', async () => {
+      await enable();
+      const signature = await businessProfileService.getEmailSignature();
+
+      const text = renderEmailSignatureText(signature, { brandingCompanyName: 'PicPeak', language: 'en' });
+
+      expect(text).toContain('Bahnhofstrasse 1');
+      expect(text).toContain('hello@example.com');
+      expect(text).toContain('VAT ID: CHE-123.456.789');
+      expect(text).toContain('Handelsregister Vaduz');
+      // A separator, the text equivalent of the footer's top border.
+      expect(text).toMatch(/^\n\n--\n/);
+    });
+
+    it('carries no HTML markup or entities', async () => {
+      await enable();
+      const signature = await businessProfileService.getEmailSignature();
+
+      const text = renderEmailSignatureText(signature, { brandingCompanyName: 'PicPeak', language: 'en' });
+
+      expect(text).not.toContain('<');
+      expect(text).not.toContain('&middot;');
+      expect(text).not.toContain('&amp;');
+    });
+
+    it('is empty when the signature is disabled', () => {
+      expect(renderEmailSignatureText(null, {})).toBe('');
+    });
+
+    it('uses the German VAT label for a German mail', async () => {
+      await enable();
+      const signature = await businessProfileService.getEmailSignature();
+
+      expect(renderEmailSignatureText(signature, { language: 'de' })).toContain('USt-IdNr.');
+      expect(renderEmailSignatureText(signature, { language: 'en' })).toContain('VAT ID');
+    });
+
+    it('does not repeat the branding company name', async () => {
+      await enable();
+      const signature = await businessProfileService.getEmailSignature();
+
+      const text = renderEmailSignatureText(signature, {
+        brandingCompanyName: 'Müller Fotografie GmbH', language: 'en',
+      });
+      expect(text).not.toContain('Müller Fotografie GmbH');
+    });
+  });
+
+  it('leaves the plain-text part free of signature markup', async () => {
+    const { htmlToText } = require('../../src/services/emailProcessor');
+    await enable();
+
+    const text = htmlToText(await wrapEmailHtml('<p>Body</p>', 'Subject'));
+
+    expect(text).toContain('Bahnhofstrasse 1');
+    expect(text).not.toContain('<p');
+    expect(text).not.toContain('style=');
+    expect(text).not.toContain('&middot;');
+    // The separator survives as a real character, not an entity.
+    expect(text).toContain('Bahnhofstrasse 1 \u00b7 Postfach 42');
+  });
+});
diff --git a/backend/migrations/core/198_business_profile_email_signature.js b/backend/migrations/core/198_business_profile_email_signature.js
new file mode 100644
index 00000000..87a5aed1
--- /dev/null
+++ b/backend/migrations/core/198_business_profile_email_signature.js
@@ -0,0 +1,46 @@
+/**
+ * `business_profile.email_signature_enabled` + `email_signature_extra` —
+ * the global email footer signature (issue #1264).
+ *
+ * The business profile already carries the full issuer block (address,
+ * phone, email, website, VAT id) but none of it ever reached an email:
+ * those columns only feed the quote/invoice PDF renderer and the public
+ * quote page. Every outgoing mail footer was the fixed logo + company
+ * name + copyright line built inside `wrapEmailHtml`.
+ *
+ * Rather than copy the address into a second place, the wrapper now reads
+ * this profile row. These two columns are the only new state: a master
+ * toggle and one free-text line for the legal notice (Handelsregister /
+ * registration number / disclaimer) that has no dedicated column.
+ *
+ * Default FALSE on purpose: an upgraded install keeps a byte-identical
+ * footer until an admin turns the signature on.
+ */
+
+exports.up = async function (knex) {
+  if (!(await knex.schema.hasTable('business_profile'))) return;
+
+  if (!(await knex.schema.hasColumn('business_profile', 'email_signature_enabled'))) {
+    await knex.schema.alterTable('business_profile', (table) => {
+      table.boolean('email_signature_enabled').notNullable().defaultTo(false);
+    });
+  }
+  if (!(await knex.schema.hasColumn('business_profile', 'email_signature_extra'))) {
+    await knex.schema.alterTable('business_profile', (table) => {
+      // Plain text, rendered escaped and <br>-separated. Not HTML.
+      table.text('email_signature_extra');
+    });
+  }
+};
+
+exports.down = async function (knex) {
+  if (!(await knex.schema.hasTable('business_profile'))) return;
+
+  for (const column of ['email_signature_enabled', 'email_signature_extra']) {
+    if (await knex.schema.hasColumn('business_profile', column)) {
+      await knex.schema.alterTable('business_profile', (table) => {
+        table.dropColumn(column);
+      });
+    }
+  }
+};
diff --git a/backend/src/routes/adminBusinessProfile.js b/backend/src/routes/adminBusinessProfile.js
index 971cef84..ce5fb4f6 100644
--- a/backend/src/routes/adminBusinessProfile.js
+++ b/backend/src/routes/adminBusinessProfile.js
@@ -179,6 +179,12 @@ function transformProfile(p) {
       : (p.scheduled_email_floor_enabled === true
         || p.scheduled_email_floor_enabled === 1
         || p.scheduled_email_floor_enabled === '1'),
+    // Migration 198 — global email footer signature. Defaults FALSE so an
+    // upgraded install's footer stays byte-identical until an admin opts in.
+    emailSignatureEnabled: p.email_signature_enabled === true
+      || p.email_signature_enabled === 1
+      || p.email_signature_enabled === '1',
+    emailSignatureExtra: p.email_signature_extra || '',
     createdAt: p.created_at,
     updatedAt: p.updated_at,
   };
@@ -456,6 +462,11 @@ router.put(
     }),
     // Migration 114 — scheduled-email floor master switch.
     body('scheduledEmailFloorEnabled').optional().isBoolean(),
+    // Migration 198 — global email footer signature. Boolean uses the
+    // explicit-undefined form so `false` reaches the service and the
+    // toggle can actually be switched off.
+    body('emailSignatureEnabled').optional().isBoolean(),
+    body('emailSignatureExtra').optional({ values: 'falsy' }).isString().isLength({ max: 500 }),
   ],
   handleAsync(async (req, res) => {
     validateRequest(req);
@@ -497,6 +508,9 @@ router.put(
       // Migration 114 — business hours + scheduled-email floor switch.
       businessHours: 'business_hours',
       scheduledEmailFloorEnabled: 'scheduled_email_floor_enabled',
+      // Migration 198 — global email footer signature.
+      emailSignatureEnabled: 'email_signature_enabled',
+      emailSignatureExtra: 'email_signature_extra',
     };
     for (const [api, db] of Object.entries(map)) {
       if (Object.prototype.hasOwnProperty.call(req.body, api)) {
diff --git a/backend/src/routes/adminEmail.js b/backend/src/routes/adminEmail.js
index ecbd3eb0..c7a016f1 100644
--- a/backend/src/routes/adminEmail.js
+++ b/backend/src/routes/adminEmail.js
@@ -8,8 +8,9 @@ const { requirePermission } = require('../middleware/permissions');
 // /email mount — the pre-existing config/queue/received endpoints stay ungated).
 const { requireFeatureFlag } = require('../middleware/requireFeatureFlag');
 const messagingGate = requireFeatureFlag('messaging');
-const { wrapEmailHtml, processEmailQueue, resolveFromIdentity } = require('../services/emailProcessor');
+const { wrapEmailHtml, processEmailQueue, resolveFromIdentity, buildSignatureTextFor, htmlToText } = require('../services/emailProcessor');
 const emailWebhookTransport = require('../services/emailWebhookTransport');
+const businessProfileService = require('../services/businessProfileService');
 const { errorResponse, safeValidationErrors } = require('../utils/routeHelpers');
 const logger = require('../utils/logger');
 const router = express.Router();
@@ -494,7 +495,10 @@ router.post('/test', adminAuth, requirePermission('email.send'), async (req, res
           to: test_email,
           subject: webhookSubject,
           html: webhookHtml,
-          text: 'Test Email Successful! Delivered through the configured email webhook.',
+          // The HTML goes through wrapEmailHtml and gains the signature; the
+          // text alternative has to be given it explicitly (#1264 review).
+          text: 'Test Email Successful! Delivered through the configured email webhook.'
+            + await buildSignatureTextFor('en'),
         });
       } catch (webhookError) {
         // Handled here, not by the outer catch: that one maps ECONNREFUSED and
@@ -580,6 +584,7 @@ router.post('/test', adminAuth, requirePermission('email.send'), async (req, res
       subject,
       html: wrappedHtml,
       text: 'Test Email Successful! Your email configuration is working correctly.'
+        + await buildSignatureTextFor('en')
     });
 
     res.json({ message: 'Test email sent successfully' });
@@ -1233,8 +1238,21 @@ router.post('/templates/:key/preview', adminAuth, requirePermission('email.view'
     res.json({
       subject,
       body_html: wrappedHtml,
-      body_text: textContent,
-      language
+      // The Text tab has to show what a text-only client will receive, which
+      // includes the signature the HTML tab already displays (#1264 review).
+      //
+      // The `|| htmlToText(...)` half mirrors sendTemplateEmail: a
+      // translation may legitimately have HTML and an EMPTY body_text, and
+      // the real send derives the text part from the HTML in that case.
+      // Concatenating the signature onto '' produced a non-empty string, so
+      // the Text tab rendered a footer with no message above it.
+      body_text: (textContent || htmlToText(wrappedHtml))
+        + await buildSignatureTextFor(language),
+      language,
+      // Migration 198 — the wrapper above already rendered the global
+      // signature into body_html when it's on. This flag just lets the
+      // preview UI say so, and point at Business profile when it's off.
+      signature: (await businessProfileService.getEmailSignature()) !== null
     });
   } catch (error) {
     errorResponse(res, error, 500, 'Failed to preview email template');
diff --git a/backend/src/services/businessProfileService.js b/backend/src/services/businessProfileService.js
index 7922aaff..f7d3bb8a 100644
--- a/backend/src/services/businessProfileService.js
+++ b/backend/src/services/businessProfileService.js
@@ -85,6 +85,11 @@ const ALLOWED_PROFILE_FIELDS = [
   'business_hours',
   // Master switch for the scheduled-email business-hours floor (mig 114).
   'scheduled_email_floor_enabled',
+  // Global email footer signature (migration 198). The toggle plus one
+  // free-text legal line; every other value in the signature is read from
+  // the address/contact columns above, so there is no second copy.
+  'email_signature_enabled',
+  'email_signature_extra',
 ];
 
 const ALLOWED_BANK_FIELDS = [
@@ -125,6 +130,28 @@ function normaliseCountryCode(cc) {
   return String(cc).trim().toUpperCase().slice(0, 2);
 }
 
+/**
+ * Coerce an API boolean, honouring the string forms express-validator's
+ * `isBoolean()` accepts.
+ *
+ * `Boolean('false')` and `Boolean('0')` are both TRUE, so a URL-encoded or
+ * form-encoded client sending `emailSignatureEnabled=false` passed validation
+ * and then stored the toggle as ENABLED — the one value it was trying to
+ * clear. JSON clients were unaffected, which is why it was easy to miss.
+ *
+ * Applied to every boolean in this file, not just the new one: the PDF
+ * visibility toggles, the scheduled-email floor and the bank-account default
+ * flag all shared the coercion and therefore the bug.
+ */
+function toBoolean(value) {
+  if (typeof value === 'string') {
+    const v = value.trim().toLowerCase();
+    if (v === 'false' || v === '0') return false;
+    if (v === 'true' || v === '1') return true;
+  }
+  return Boolean(value);
+}
+
 function sanitiseProfilePayload(payload) {
   const updates = pickFields(payload, ALLOWED_PROFILE_FIELDS);
 
@@ -142,7 +169,8 @@ function sanitiseProfilePayload(payload) {
   // when the admin pastes from a printed letterhead.
   for (const field of ['company_name', 'address_line1', 'address_line2',
     'city', 'state', 'country_name', 'phone', 'mobile', 'email', 'website',
-    'vat_id', 'tax_id', 'vat_label', 'footer_line', 'logo_path']) {
+    'vat_id', 'tax_id', 'vat_label', 'footer_line', 'logo_path',
+    'email_signature_extra']) {
     if (typeof updates[field] === 'string') {
       updates[field] = updates[field].trim();
     }
@@ -154,7 +182,7 @@ function sanitiseProfilePayload(payload) {
     'pdf_quote_show_net_days', 'pdf_quote_show_skonto',
   ]) {
     if (updates[field] !== undefined) {
-      updates[field] = formatBoolean(Boolean(updates[field]));
+      updates[field] = formatBoolean(toBoolean(updates[field]));
     }
   }
   // Folding-mark enum — whitelisted set. Garbage values fall back to
@@ -195,7 +223,12 @@ function sanitiseProfilePayload(payload) {
     }
   }
   if (updates.scheduled_email_floor_enabled !== undefined) {
-    updates.scheduled_email_floor_enabled = formatBoolean(Boolean(updates.scheduled_email_floor_enabled));
+    updates.scheduled_email_floor_enabled = formatBoolean(toBoolean(updates.scheduled_email_floor_enabled));
+  }
+  // Migration 198 — email footer signature master switch. Same
+  // explicit-undefined shape as the PDF toggles so `false` persists.
+  if (updates.email_signature_enabled !== undefined) {
+    updates.email_signature_enabled = formatBoolean(toBoolean(updates.email_signature_enabled));
   }
 
   return updates;
@@ -214,7 +247,7 @@ function sanitiseBankPayload(payload) {
     updates.currency = normaliseCurrency(updates.currency);
   }
   if (updates.is_default !== undefined) {
-    updates.is_default = formatBoolean(Boolean(updates.is_default));
+    updates.is_default = formatBoolean(toBoolean(updates.is_default));
   }
   for (const field of ['label', 'account_holder']) {
     if (typeof updates[field] === 'string') {
@@ -264,6 +297,10 @@ async function updateProfile(payload, adminId) {
     await db('business_profile').where({ id: 1 }).update(updates);
   });
 
+  // The email footer signature is built from these same columns, so any
+  // profile write invalidates it — not just the two signature fields.
+  invalidateEmailSignatureCache();
+
   logger.info('Business profile updated', {
     adminId,
     fields: Object.keys(updates).filter((k) => k !== 'updated_at'),
@@ -369,9 +406,84 @@ async function resolveBankAccountForCurrency(currency, overrideId = null, conn =
   });
 }
 
+/**
+ * The global email footer signature (migration 198).
+ *
+ * `wrapEmailHtml` calls this on every single outgoing mail — transactional,
+ * preview, test and manual alike — so it is memoised for 60 s and cleared
+ * on any profile write. A queue tick sending 10 mails hits the DB once.
+ *
+ * Returns `null` when the toggle is off (or the table/column is missing on
+ * an install that hasn't migrated yet), which is the wrapper's signal to
+ * render exactly the footer it rendered before this feature existed.
+ *
+ * Every value is raw text — escaping is the renderer's job.
+ */
+const SIGNATURE_CACHE_TTL_MS = 60 * 1000;
+let signatureCache = { value: undefined, expiresAt: 0 };
+
+function invalidateEmailSignatureCache() {
+  signatureCache = { value: undefined, expiresAt: 0 };
+}
+
+function truthy(v) {
+  return v === true || v === 1 || v === '1' || v === 't' || v === 'true';
+}
+
+async function getEmailSignature() {
+  const now = Date.now();
+  if (signatureCache.value !== undefined && signatureCache.expiresAt > now) {
+    return signatureCache.value;
+  }
+
+  let signature = null;
+  try {
+    const profile = await withRetry(async () =>
+      db('business_profile').where({ id: 1 }).first()
+    );
+
+    if (profile && truthy(profile.email_signature_enabled)) {
+      // Same "PC City / Country" shape the PDF issuer block uses
+      // (pdfService.js:361). The locale-aware country lookup lives in the
+      // PDF renderer; an email footer takes the free-text `country_name`
+      // when the admin set one and the ISO code otherwise.
+      const cc = profile.country_code ? String(profile.country_code).toUpperCase() : '';
+      const pc = profile.postal_code || '';
+      const left = [cc && pc ? `${cc}-${pc}` : (pc || cc), profile.city || ''].filter(Boolean).join(' ');
+      const country = profile.country_name || '';
+      const cityCountry = [left, country].filter(Boolean).join(' / ');
+
+      signature = {
+        companyName: profile.company_name || '',
+        addressLines: [profile.address_line1, profile.address_line2, cityCountry]
+          .map((l) => (l == null ? '' : String(l).trim()))
+          .filter(Boolean),
+        phone: profile.phone || '',
+        mobile: profile.mobile || '',
+        email: profile.email || '',
+        website: profile.website || '',
+        vatId: profile.vat_id || '',
+        extra: profile.email_signature_extra || '',
+      };
+    }
+  } catch (error) {
+    // A missing table/column (pre-198 install mid-upgrade) must never break
+    // the mail itself — fall through to "no signature".
+    logger.warn('Could not read email signature from business profile', {
+      error: error.message,
+    });
+    signature = null;
+  }
+
+  signatureCache = { value: signature, expiresAt: now + SIGNATURE_CACHE_TTL_MS };
+  return signature;
+}
+
 module.exports = {
   getProfile,
   updateProfile,
+  getEmailSignature,
+  invalidateEmailSignatureCache,
   createBankAccount,
   updateBankAccount,
   deleteBankAccount,
diff --git a/backend/src/services/emailProcessor.js b/backend/src/services/emailProcessor.js
index 6d0aab60..a291c0a9 100644
--- a/backend/src/services/emailProcessor.js
+++ b/backend/src/services/emailProcessor.js
@@ -8,6 +8,9 @@ const {
 } = require('../utils/businessHours');
 const { hasColumnCached } = require('../utils/schemaCache');
 const emailWebhookTransport = require('./emailWebhookTransport');
+// Migration 198 — the global email footer signature is read from the
+// business profile. No cycle: businessProfileService only pulls db + utils.
+const businessProfileService = require('./businessProfileService');
 
 /**
  * The From identity for an outbound message (#1225).
@@ -230,6 +233,137 @@ function darkenColor(hex, amount = 0.15) {
   return `#${(1 << 24 | Math.round(r) << 16 | Math.round(g) << 8 | Math.round(b)).toString(16).slice(1)}`;
 }
 
+// ---- global email footer signature (migration 198, issue #1264) --------
+//
+// Built from the business_profile issuer block — the address, contact rows
+// and legal line the operator already maintains for their invoices — so it
+// appears under EVERY mail this install sends without a single template
+// being touched. Returns '' when the admin has not enabled it, which keeps
+// the footer byte-identical to what pre-198 installs render.
+
+// VAT is the one value that needs a label to mean anything. en/de only;
+// every other locale falls back to the English label, same as the rest of
+// the wrapper chrome ("All rights reserved").
+const SIGNATURE_VAT_LABELS = { en: 'VAT ID', de: 'USt-IdNr.' };
+
+// tel: hrefs take digits and a leading +; strip everything else so a pasted
+// "+41 79 123 45 67 (mobile only)" can't smuggle a scheme or a quote into
+// the attribute.
+function signatureTelHref(raw) {
+  const cleaned = String(raw || '').replace(/[^\d+]/g, '');
+  return cleaned ? `tel:${cleaned}` : null;
+}
+
+// Admins type "example.com" as often as "https://example.com". Anything not
+// already http(s) gets an https:// prefix — which also means a pasted
+// `javascript:` value becomes an inert https URL instead of a live scheme.
+function signatureWebsiteHref(raw) {
+  const trimmed = String(raw || '').trim();
+  if (!trimmed) return null;
+  return /^https?:\/\//i.test(trimmed) ? trimmed : `https://${trimmed}`;
+}
+
+function renderSignatureLink(href, text, color) {
+  return `<a href="${escapeHtml(href)}" style="color:${color};text-decoration:none;">${escapeHtml(text)}</a>`;
+}
+
+/**
+ * @param {object|null} signature  businessProfileService.getEmailSignature()
+ * @param {object} opts  { mutedTextColor, brandingCompanyName, language }
+ * @returns {string} HTML rows for the footer <td>, or '' when disabled.
+ */
+function renderEmailSignature(signature, { mutedTextColor, brandingCompanyName, language }) {
+  if (!signature) return '';
+
+  const lineStyle = `color:${mutedTextColor};font-size:12px;line-height:18px;margin:4px 0;`;
+  const rows = [];
+
+  // The footer above already prints the BRANDING company name. Only repeat
+  // the profile's when the operator has actually given it a different legal
+  // name ("Foto Müller" vs "Müller Fotografie GmbH").
+  if (signature.companyName && signature.companyName !== brandingCompanyName) {
+    rows.push(`<p style="${lineStyle}">${escapeHtml(signature.companyName)}</p>`);
+  }
+
+  // A literal middle dot, not `&middot;`: the plain-text part of every mail
+  // is derived from this HTML by htmlToText, which decodes only the five
+  // core entities — an `&middot;` would survive verbatim into the text body.
+  if (signature.addressLines.length) {
+    rows.push(`<p style="${lineStyle}">${signature.addressLines.map(escapeHtml).join(' \u00b7 ')}</p>`);
+  }
+
+  const contact = [];
+  for (const number of [signature.phone, signature.mobile]) {
+    const href = signatureTelHref(number);
+    if (href) contact.push(renderSignatureLink(href, number, mutedTextColor));
+  }
+  if (signature.email) {
+    contact.push(renderSignatureLink(`mailto:${signature.email}`, signature.email, mutedTextColor));
+  }
+  const website = signatureWebsiteHref(signature.website);
+  if (website) contact.push(renderSignatureLink(website, signature.website, mutedTextColor));
+  if (contact.length) {
+    rows.push(`<p style="${lineStyle}">${contact.join(' \u00b7 ')}</p>`);
+  }
+
+  if (signature.vatId) {
+    const label = SIGNATURE_VAT_LABELS[language] || SIGNATURE_VAT_LABELS.en;
+    rows.push(`<p style="${lineStyle}">${escapeHtml(label)}: ${escapeHtml(signature.vatId)}</p>`);
+  }
+
+  // Free text (Handelsregister line, disclaimer, …). Plain text, never
+  // HTML — escaped, then newlines become <br> so a pasted 3-line legal
+  // notice keeps its shape.
+  if (signature.extra) {
+    const extra = escapeHtml(signature.extra).replace(/\r\n|\r|\n/g, '<br />');
+    rows.push(`<p style="${lineStyle}font-size:11px;">${extra}</p>`);
+  }
+
+  if (!rows.length) return '';
+
+  return `
+              <div style="margin:15px 0 5px;padding-top:15px;border-top:1px solid #eeeeee;">
+                ${rows.join('\n                ')}
+              </div>`;
+}
+
+/**
+ * The signature as plain text, for the text/plain MIME alternative.
+ *
+ * `sendTemplateEmail` uses a template's own `body_text` when it has one — and
+ * the seeded templates all do — so the text part is NOT derived from the
+ * wrapped HTML and would otherwise carry no signature at all. A text-only
+ * client, and the preview's Text tab, then showed a mail with no address and
+ * no legal line while the HTML part had both.
+ *
+ * Returns '' when the signature is disabled, so callers can append
+ * unconditionally.
+ */
+function renderEmailSignatureText(signature, { brandingCompanyName, language } = {}) {
+  if (!signature) return '';
+
+  const lines = [];
+  if (signature.companyName && signature.companyName !== brandingCompanyName) {
+    lines.push(signature.companyName);
+  }
+  if (signature.addressLines.length) {
+    lines.push(signature.addressLines.join(' \u00b7 '));
+  }
+  const contact = [signature.phone, signature.mobile, signature.email, signature.website]
+    .map((v) => (v || '').trim())
+    .filter(Boolean);
+  if (contact.length) lines.push(contact.join(' \u00b7 '));
+  if (signature.vatId) {
+    const label = SIGNATURE_VAT_LABELS[language] || SIGNATURE_VAT_LABELS.en;
+    lines.push(`${label}: ${signature.vatId}`);
+  }
+  if (signature.extra) lines.push(signature.extra);
+
+  if (!lines.length) return '';
+  // A visual separator, the plain-text equivalent of the footer's top border.
+  return `\n\n--\n${lines.join('\n')}`;
+}
+
 // Wrap HTML body in the styled email template with header, footer, and logo
 async function wrapEmailHtml(htmlBody, subject, language = 'en') {
   // Email colour palette. The two original settings (email_primary_color and
@@ -292,6 +426,14 @@ async function wrapEmailHtml(htmlBody, subject, language = 'en') {
   const logoFullUrl = `${frontendUrl}${logoPath.startsWith('/') ? '' : '/'}${logoPath}`;
   logger.debug('Email logo URL:', { frontendUrl, logoPath, logoFullUrl });
 
+  // Migration 198 — global footer signature from the business profile.
+  // Memoised for 60 s in the service, so a queue tick sending ten mails
+  // reads the row once. Never throws; returns null when disabled.
+  const signatureHtml = renderEmailSignature(
+    await businessProfileService.getEmailSignature(),
+    { mutedTextColor, brandingCompanyName: companyName, language }
+  );
+
   const year = new Date().getFullYear();
   // PR review follow-up — Outlook (Word engine) and Apple Mail under some
   // configs STRIP the <head><style>, so any element styled only by a class
@@ -438,7 +580,7 @@ async function wrapEmailHtml(htmlBody, subject, language = 'en') {
           <tr>
             <td align="center" bgcolor="${secondaryColor}" class="email-footer" style="background-color:${secondaryColor};padding:30px;text-align:center;border-top:1px solid #eeeeee;">
               <img src="${logoFullUrl}" alt="${companyName}" width="120" style="max-width:120px;height:auto;opacity:0.8;margin-bottom:15px;border:0;">
-              <p style="color:${mutedTextColor};font-size:14px;margin:5px 0;">${companyName}</p>
+              <p style="color:${mutedTextColor};font-size:14px;margin:5px 0;">${companyName}</p>${signatureHtml}
               <p style="font-size:12px;color:#999999;margin:5px 0;">© ${year} ${companyName}. All rights reserved.</p>
             </td>
           </tr>
@@ -736,6 +878,28 @@ async function processTemplate(template, variables, language = 'en') {
 }
 
 // Send email using template
+/**
+ * Resolve the signature and render its plain-text form for `language`.
+ * Never throws — a footer must not be able to fail a send.
+ */
+async function buildSignatureTextFor(language) {
+  try {
+    const signature = await businessProfileService.getEmailSignature();
+    if (!signature) return '';
+    let brandingCompanyName = 'PicPeak';
+    try {
+      const row = await db('app_settings').where('setting_key', 'branding_company_name').first();
+      if (row && row.setting_value) {
+        try { brandingCompanyName = JSON.parse(row.setting_value); } catch (_) { brandingCompanyName = row.setting_value; }
+      }
+    } catch (_) { /* fall back to the default name */ }
+    return renderEmailSignatureText(signature, { brandingCompanyName, language });
+  } catch (error) {
+    logger.warn('Could not render the plain-text email signature', { error: error.message });
+    return '';
+  }
+}
+
 async function sendTemplateEmail(to, templateKey, variables) {
   try {
     // Webhook transport (#1225) replaces SMTP entirely when configured, so an
@@ -805,7 +969,12 @@ async function sendTemplateEmail(to, templateKey, variables) {
       cc: ccList,
       subject: subject,
       html: htmlBody,
-      text: textBody || htmlToText(htmlBody),
+      // When the template supplies its own body_text the text part is not
+      // derived from the wrapped HTML, so the signature has to be appended
+      // here or the text/plain alternative silently omits it (#1264 review).
+      text: textBody
+        ? textBody + await buildSignatureTextFor(language)
+        : htmlToText(htmlBody),
       attachments,
     };
     const info = viaWebhook
@@ -1274,6 +1443,8 @@ module.exports = {
   stopEmailQueueProcessor,
   testEmailConnection,
   wrapEmailHtml,
+  renderEmailSignatureText,
+  buildSignatureTextFor,
   safeTemplateReplace,
   getSupportEmail,
   htmlToText
diff --git a/backend/src/services/guestRecoveryService.js b/backend/src/services/guestRecoveryService.js
index b7a07c9d..fbac1490 100644
--- a/backend/src/services/guestRecoveryService.js
+++ b/backend/src/services/guestRecoveryService.js
@@ -85,7 +85,10 @@ async function sendRecoveryEmail(toEmail, code, eventName = 'your gallery') {
     to: toEmail,
     subject,
     html: styledHtml,
-    text: `Your verification code is ${code}. It expires in 15 minutes.`,
+    // wrapEmailHtml gives the HTML part the signature; the text
+    // alternative needs it appended explicitly (#1264 review).
+    text: `Your verification code is ${code}. It expires in 15 minutes.`
+      + await require('./emailProcessor').buildSignatureTextFor('en'),
   };
   if (viaWebhook) {
     await emailWebhookTransport.send(mail);
diff --git a/frontend/src/i18n/locales/de.json b/frontend/src/i18n/locales/de.json
index 53826f21..fe6736aa 100644
--- a/frontend/src/i18n/locales/de.json
+++ b/frontend/src/i18n/locales/de.json
@@ -3855,7 +3855,10 @@
       "requiredFields": "Host, Port und Benutzername sind erforderlich.",
       "testOk": "Verbunden mit {{folder}} — {{messages}} Nachrichten, {{unseen}} ungelesen.",
       "testFailed": "Verbindung fehlgeschlagen."
-    }
+    },
+    "signatureOn": "Fusszeilen-Signatur ist an — Ihre Geschäftsadresse wird an automatische E-Mails angehängt. Antworten, die Sie unter Nachrichten schreiben, werden unverändert gesendet.",
+    "signatureOff": "Fusszeilen-Signatur ist aus — E-Mails zeigen nur Logo und Firmenname.",
+    "signatureEdit": "Im Geschäftsprofil bearbeiten"
   },
   "cms": {
     "title": "CMS-Seiten",
@@ -6113,7 +6116,19 @@
     "logoUploadedToast": "PDF-Logo hochgeladen.",
     "logoConfirmClear": "PDF-Logo entfernen? Der Renderer greift dann auf das Branding-Logo zurück, sofern eines hinterlegt ist.",
     "logoClearedToast": "PDF-Logo entfernt.",
-    "bankUpdatedToast": "Bankverbindung aktualisiert."
+    "bankUpdatedToast": "Bankverbindung aktualisiert.",
+    "emailSignature": {
+      "title": "E-Mail-Signatur",
+      "subtitle": "Hängt Ihre Firmendaten an die Fusszeile jeder E-Mail an, die diese Installation versendet. Wird aus den Adress- und Kontaktfeldern oben gebildet — nichts wird doppelt erfasst.",
+      "toggle": "Signatur in E-Mail-Fusszeilen anzeigen",
+      "toggleHelp": "Wenn aus, behalten E-Mails die schlichte Fusszeile mit Logo und Firmenname. Gilt für jede automatische E-Mail — Galerie-Benachrichtigungen, Offerten, Rechnungen, Erinnerungen — sowie für Testversand und Vorschau. Antworten, die Sie selbst unter Nachrichten schreiben, werden unverändert gesendet und erhalten keine Signatur.",
+      "extra": "Rechtliche Zeile (optional)",
+      "extraPlaceholder": "Handelsregister Vaduz FL-0002.123.456-7",
+      "extraHelp": "Registernummer, Haftungsausschluss oder jede Zeile ohne eigenes Feld. Reiner Text, maximal 500 Zeichen.",
+      "previewTitle": "Vorschau der Fusszeile",
+      "previewOff": "Signatur ist aus — E-Mails zeigen nur Logo und Firmenname.",
+      "previewEmpty": "Signatur ist an, aber alle Felder oben sind leer — es wird nichts an die Fusszeile angehängt."
+    }
   },
   "crmSettings": {
     "savedToast": "CRM-Einstellungen gespeichert.",
diff --git a/frontend/src/i18n/locales/en.json b/frontend/src/i18n/locales/en.json
index 6f25dc0b..c3a7a030 100644
--- a/frontend/src/i18n/locales/en.json
+++ b/frontend/src/i18n/locales/en.json
@@ -3368,7 +3368,10 @@
       "requiredFields": "Host, port and username are required.",
       "testOk": "Connected to {{folder}} — {{messages}} messages, {{unseen}} unread.",
       "testFailed": "Connection failed."
-    }
+    },
+    "signatureOn": "Footer signature is on — your business address is appended to automatic emails. Replies you write in Messages are sent as typed.",
+    "signatureOff": "Footer signature is off — emails show the logo and company name only.",
+    "signatureEdit": "Edit in Business profile"
   },
   "cms": {
     "title": "CMS Pages",
@@ -6112,7 +6115,19 @@
     "logoUploadedToast": "PDF logo uploaded.",
     "logoConfirmClear": "Remove the PDF logo? The renderer will fall back to the Branding logo if one is set.",
     "logoClearedToast": "PDF logo removed.",
-    "bankUpdatedToast": "Bank account updated."
+    "bankUpdatedToast": "Bank account updated.",
+    "emailSignature": {
+      "title": "Email signature",
+      "subtitle": "Append your company details to the footer of every email this installation sends. Built from the address and contact fields above — nothing is duplicated.",
+      "toggle": "Show signature in email footers",
+      "toggleHelp": "When off, emails keep the plain logo + company name footer. Applies to every automatic email — gallery notices, quotes, invoices, reminders — plus test sends and previews. Replies you write yourself in Messages are sent as typed and do not get the signature.",
+      "extra": "Legal line (optional)",
+      "extraPlaceholder": "Handelsregister Vaduz FL-0002.123.456-7",
+      "extraHelp": "Registration number, disclaimer or any line with no field of its own. Plain text, up to 500 characters.",
+      "previewTitle": "Footer preview",
+      "previewOff": "Signature is off — emails show the logo and company name only.",
+      "previewEmpty": "Signature is on but every field above is blank — nothing will be added to the footer."
+    }
   },
   "crmSettings": {
     "savedToast": "CRM settings saved.",
diff --git a/frontend/src/pages/admin/EmailConfigPage.tsx b/frontend/src/pages/admin/EmailConfigPage.tsx
index a1571626..bdae4497 100644
--- a/frontend/src/pages/admin/EmailConfigPage.tsx
+++ b/frontend/src/pages/admin/EmailConfigPage.tsx
@@ -23,10 +23,12 @@ import { ReceivedEmailsPanel } from '../../components/admin/ReceivedEmailsPanel'
 import { IncomingMailConfigCard } from '../../components/admin/IncomingMailConfigCard';
 import { CustomerMailboxCard } from '../../components/admin/CustomerMailboxCard';
 import { Palette, RefreshCw, Info } from 'lucide-react';
+import { Link } from 'react-router-dom';
 import { useQuery, useMutation } from '@tanstack/react-query';
 import { useModal, useMutationWithToast } from '../../hooks';
 import { emailService, type EmailConfig, type EmailTemplate, type EmailTemplateTranslation } from '../../services/email.service';
 import { settingsService } from '../../services/settings.service';
+import { businessProfileService } from '../../services/businessProfile.service';
 import { useTranslation } from 'react-i18next';
 import { SUPPORTED_LANGUAGES } from "../../components/common/LanguageSelector.tsx";
 import { useFeatureFlags, type FeatureKey } from '../../contexts/FeatureFlagsContext';
@@ -210,6 +212,27 @@ export const EmailConfigPage: React.FC = () => {
     tls_reject_unauthorized: true
   });
 
+  // Migration 198 — whether the global footer signature is on. Read-only
+  // here; the toggle itself lives on Settings → Business profile.
+  //
+  // This tab is reachable with `email.view`, but GET /admin/business-profile
+  // requires `settings.view` / `settings.banking`. An email-only role gets a
+  // 403, and reporting that as "signature is off" would be stating something
+  // false about a mail they are about to send — so an unreadable profile
+  // renders nothing at all rather than a guess (#1264 review).
+  const { data: businessProfile, isError, isPending } = useQuery({
+    queryKey: ['business-profile'],
+    queryFn: () => businessProfileService.get(),
+    enabled: activeTab === 'smtp',
+    retry: false,
+  });
+  // Pending counts as unknown too. The other queries on this tab are often
+  // cached and paint first, so `?? false` announced "signature is off" for
+  // as long as this request was in flight — a wrong statement about a mail
+  // the admin is about to send, not merely a slow one.
+  const signatureUnknown = isError || isPending || !businessProfile;
+  const signatureEnabled = businessProfile?.profile?.emailSignatureEnabled ?? false;
+
   // Fetch SMTP config
   const { isLoading: configLoading } = useQuery({
     queryKey: ['email-config'],
@@ -536,6 +559,24 @@ export const EmailConfigPage: React.FC = () => {
       {/* SMTP Settings Tab */}
       {activeTab === 'smtp' && (
         <div className="grid grid-cols-1 lg:grid-cols-2 gap-6">
+          {/* The footer signature (migration 198) is applied by the email
+              wrapper to every send from this page, but it's configured on
+              the Business profile — point at it from where the mail is set
+              up rather than making the operator hunt for it. */}
+          {!signatureUnknown && (
+          <div className="lg:col-span-2 flex items-start gap-2 rounded-md border border-neutral-200 dark:border-neutral-700 bg-neutral-50 dark:bg-neutral-800/60 p-3 text-sm text-neutral-600 dark:text-neutral-400">
+            <Info className="w-4 h-4 mt-0.5 shrink-0" />
+            <span>
+              {signatureEnabled
+                ? t('email.signatureOn', 'Footer signature is on — your business address is appended to automatic emails. Replies you write in Messages are sent as typed.')
+                : t('email.signatureOff', 'Footer signature is off — emails show the logo and company name only.')}
+              {' '}
+              <Link to="/admin/settings?tab=businessProfile" className="underline hover:no-underline" style={{ color: 'var(--color-accent)' }}>
+                {t('email.signatureEdit', 'Edit in Business profile')}
+              </Link>
+            </span>
+          </div>
+          )}
           <Card padding="md">
             <h2 className="text-lg font-semibold text-neutral-900 dark:text-neutral-100 mb-4">{t('email.smtpConfiguration')}</h2>
 
diff --git a/frontend/src/pages/admin/settings/SettingsBusinessProfilePage.tsx b/frontend/src/pages/admin/settings/SettingsBusinessProfilePage.tsx
index fee1effb..2f579176 100644
--- a/frontend/src/pages/admin/settings/SettingsBusinessProfilePage.tsx
+++ b/frontend/src/pages/admin/settings/SettingsBusinessProfilePage.tsx
@@ -8,7 +8,7 @@
 import React, { useEffect, useState } from 'react';
 import { useTranslation } from 'react-i18next';
 import { useMutation, useQuery, useQueryClient } from '@tanstack/react-query';
-import { Plus, Trash2, Star, Pencil, Save, Clock, Copy } from 'lucide-react';
+import { Plus, Trash2, Star, Pencil, Save, Clock, Copy, Mail } from 'lucide-react';
 import {
   businessProfileService,
   type BusinessProfile,
@@ -305,6 +305,58 @@ export const SettingsBusinessProfilePage: React.FC = () => {
         </div>
       </Card>
 
+      {/* Global email footer signature (migration 198, issue #1264).
+          Rendered by wrapEmailHtml only, so flipping this toggle changes
+          the footer of EVERY outgoing mail — transactional, preview, test
+          and manual — without any per-template edit. Every value except
+          the legal line below comes from the fields already on this page. */}
+      <Card>
+        <div className="flex items-center gap-2 mb-1">
+          <Mail className="w-5 h-5 text-neutral-500" />
+          <h3 className="font-semibold text-neutral-900 dark:text-neutral-100">
+            {t('businessProfile.emailSignature.title', 'Email signature')}
+          </h3>
+        </div>
+        <p className="text-sm text-neutral-600 dark:text-neutral-400 mb-4">
+          {t('businessProfile.emailSignature.subtitle',
+            'Append your company details to the footer of every email this installation sends. Built from the address and contact fields above — nothing is duplicated.')}
+        </p>
+
+        <PdfToggleRow
+          label={t('businessProfile.emailSignature.toggle', 'Show signature in email footers') as string}
+          description={t('businessProfile.emailSignature.toggleHelp',
+            'When off, emails keep the plain logo + company name footer. Applies to every automatic email — gallery notices, quotes, invoices, reminders — plus test sends and previews. Replies you write yourself in Messages are sent as typed and do not get the signature.') as string}
+          enabled={profile.emailSignatureEnabled}
+          onChange={(v) => setProfile({ ...profile, emailSignatureEnabled: v })}
+        />
+
+        <div className="mt-4">
+          <label className="block text-sm font-medium text-neutral-700 dark:text-neutral-300 mb-1">
+            {t('businessProfile.emailSignature.extra', 'Legal line (optional)')}
+          </label>
+          <textarea
+            rows={3}
+            maxLength={500}
+            value={profile.emailSignatureExtra}
+            onChange={(e) => setProfile({ ...profile, emailSignatureExtra: e.target.value })}
+            placeholder={t('businessProfile.emailSignature.extraPlaceholder',
+              'Handelsregister Vaduz FL-0002.123.456-7') as string}
+            className="w-full rounded-md border border-neutral-300 dark:border-neutral-600 bg-white dark:bg-neutral-800 px-3 py-2 text-sm text-neutral-900 dark:text-neutral-100"
+          />
+          <p className="mt-1 text-xs text-neutral-500 dark:text-neutral-400">
+            {t('businessProfile.emailSignature.extraHelp',
+              'Registration number, disclaimer or any line with no field of its own. Plain text, up to 500 characters.')}
+          </p>
+        </div>
+
+        <div className="mt-4 pt-4 border-t border-neutral-200 dark:border-neutral-700">
+          <p className="text-xs font-medium text-neutral-500 dark:text-neutral-400 mb-2 uppercase tracking-wide">
+            {t('businessProfile.emailSignature.previewTitle', 'Footer preview')}
+          </p>
+          <EmailSignaturePreview profile={profile} />
+        </div>
+      </Card>
+
       {/* Disclaimer banner for QR-bill / IBAN data. picpeak renders
           what the operator types — it cannot validate IBAN/BIC, QR-IID
           or scan-compatibility with any specific bank's e-banking app.
@@ -361,6 +413,64 @@ const PdfToggleRow: React.FC<PdfToggleRowProps> = ({ label, description, enabled
   </label>
 );
 
+/**
+ * Read-only render of the email footer signature (migration 198).
+ *
+ * Deliberately mirrors `renderEmailSignature` in the backend's
+ * emailProcessor: same field order, same middle-dot separators, same
+ * omit-when-empty rule. It is a preview, not a second renderer — the mail
+ * itself is always built server-side.
+ */
+const EmailSignaturePreview: React.FC<{ profile: BusinessProfile }> = ({ profile }) => {
+  const { t, i18n } = useTranslation();
+
+  if (!profile.emailSignatureEnabled) {
+    return (
+      <p className="text-sm text-neutral-500 dark:text-neutral-400 italic">
+        {t('businessProfile.emailSignature.previewOff', 'Signature is off — emails show the logo and company name only.')}
+      </p>
+    );
+  }
+
+  // "LI-9494 Schaan / Liechtenstein" — the same shape the PDF issuer
+  // block uses, assembled identically on the backend.
+  const cc = profile.countryCode ? profile.countryCode.toUpperCase() : '';
+  const pc = profile.postalCode || '';
+  const left = [cc && pc ? `${cc}-${pc}` : (pc || cc), profile.city || ''].filter(Boolean).join(' ');
+  const cityCountry = [left, profile.countryName || ''].filter(Boolean).join(' / ');
+
+  const addressLines = [profile.addressLine1, profile.addressLine2, cityCountry]
+    .map((l) => (l || '').trim())
+    .filter(Boolean);
+  const contacts = [profile.phone, profile.mobile, profile.email, profile.website]
+    .map((c) => (c || '').trim())
+    .filter(Boolean);
+  const vatLabel = i18n.language?.startsWith('de') ? 'USt-IdNr.' : 'VAT ID';
+
+  const isEmpty = !profile.companyName && !addressLines.length && !contacts.length
+    && !profile.vatId && !profile.emailSignatureExtra;
+  if (isEmpty) {
+    return (
+      <p className="text-sm text-amber-700 dark:text-amber-400">
+        {t('businessProfile.emailSignature.previewEmpty',
+          'Signature is on but every field above is blank — nothing will be added to the footer.')}
+      </p>
+    );
+  }
+
+  return (
+    <div data-testid="email-signature-preview" className="rounded-md bg-neutral-50 dark:bg-neutral-800/60 p-3 text-center text-xs text-neutral-600 dark:text-neutral-400 space-y-1">
+      {profile.companyName && <p>{profile.companyName}</p>}
+      {addressLines.length > 0 && <p>{addressLines.join(' \u00b7 ')}</p>}
+      {contacts.length > 0 && <p>{contacts.join(' \u00b7 ')}</p>}
+      {profile.vatId && <p>{vatLabel}: {profile.vatId}</p>}
+      {profile.emailSignatureExtra && (
+        <p className="text-[11px] whitespace-pre-line">{profile.emailSignatureExtra}</p>
+      )}
+    </div>
+  );
+};
+
 /**
  * Per-weekday business-hours editor (migration 114). Google-style: each
  * weekday holds zero or more {start,end} blocks, so a day can be closed
diff --git a/frontend/src/pages/admin/settings/__tests__/emailSignatureCard.test.tsx b/frontend/src/pages/admin/settings/__tests__/emailSignatureCard.test.tsx
new file mode 100644
index 00000000..74206b99
--- /dev/null
+++ b/frontend/src/pages/admin/settings/__tests__/emailSignatureCard.test.tsx
@@ -0,0 +1,164 @@
+/**
+ * Settings → Business profile — email signature card (migration 198, #1264).
+ *
+ * The preview here mirrors the backend's `renderEmailSignature`, so the
+ * cases worth pinning are the ones where the two could silently drift:
+ * the "LI-9494 Schaan / Liechtenstein" city line, the middle-dot joins,
+ * and the omit-when-empty rule. Plus the two states an operator can land
+ * in and misread — signature off, and signature on with a blank profile.
+ */
+import { render, screen, within } from '@testing-library/react';
+import userEvent from '@testing-library/user-event';
+import { vi } from 'vitest';
+import { QueryClient, QueryClientProvider } from '@tanstack/react-query';
+
+import type { BusinessProfile } from '../../../../services/businessProfile.service';
+
+vi.mock('react-i18next', async () => {
+  const actual = await vi.importActual<typeof import('react-i18next')>('react-i18next');
+  return {
+    ...actual,
+    useTranslation: () => ({
+      t: (k: string, fb?: unknown) => (typeof fb === 'string' ? fb : k),
+      i18n: { language: 'en' },
+    }),
+  };
+});
+
+vi.mock('react-toastify', () => ({ toast: { success: vi.fn(), error: vi.fn() } }));
+
+const baseProfile: BusinessProfile = {
+  id: 1,
+  companyName: 'Müller Fotografie GmbH',
+  addressLine1: 'Bahnhofstrasse 1',
+  addressLine2: '',
+  postalCode: '9494',
+  city: 'Schaan',
+  state: '',
+  countryCode: 'LI',
+  countryName: 'Liechtenstein',
+  phone: '+41 79 123 45 67',
+  mobile: '',
+  email: 'hello@example.com',
+  website: 'example.com',
+  vatId: 'CHE-123.456.789',
+  taxId: '',
+  vatLabel: 'MwSt.',
+  vatRateDefault: null,
+  defaultHourlyRateMinor: null,
+  defaultCurrency: 'CHF',
+  defaultLocale: 'de',
+  defaultQrFormat: 'none',
+  footerLine: '',
+  logoPath: '',
+  pdfFontTtfPath: '',
+  pdfFontFamily: null,
+  pdfShowLogo: true,
+  pdfShowCompanyName: true,
+  pdfCompanyNameInline: false,
+  pdfLogoHeight: 56,
+  pdfFoldingMarks: 'none',
+  pdfQuoteShowNetDays: false,
+  pdfQuoteShowSkonto: false,
+  timezone: null,
+  businessHours: null,
+  scheduledEmailFloorEnabled: true,
+  emailSignatureEnabled: true,
+  emailSignatureExtra: 'Handelsregister Vaduz',
+  createdAt: '2026-01-01T00:00:00Z',
+  updatedAt: '2026-01-01T00:00:00Z',
+};
+
+let profileFixture: BusinessProfile = baseProfile;
+
+vi.mock('../../../../services/businessProfile.service', () => ({
+  businessProfileService: {
+    get: vi.fn(async () => ({ profile: profileFixture, bankAccounts: [] })),
+    update: vi.fn(async () => ({ profile: profileFixture, bankAccounts: [] })),
+    listBankAccounts: vi.fn(async () => ({ bankAccounts: [] })),
+    createBankAccount: vi.fn(),
+    updateBankAccount: vi.fn(),
+    deleteBankAccount: vi.fn(),
+    uploadLogo: vi.fn(),
+    clearLogo: vi.fn(),
+  },
+}));
+
+import { SettingsBusinessProfilePage } from '../SettingsBusinessProfilePage';
+
+function renderPage() {
+  const qc = new QueryClient({ defaultOptions: { queries: { retry: false } } });
+  return render(
+    <QueryClientProvider client={qc}>
+      <SettingsBusinessProfilePage />
+    </QueryClientProvider>
+  );
+}
+
+describe('email signature card', () => {
+  beforeEach(() => {
+    profileFixture = { ...baseProfile };
+  });
+
+  it('renders the signature preview from the address fields above', async () => {
+    renderPage();
+
+    // Scoped to the preview block — the legal line also lives in the
+    // textarea above it, and the company name in the form fields.
+    const preview = within(await screen.findByTestId('email-signature-preview'));
+
+    expect(preview.getByText('Müller Fotografie GmbH')).toBeInTheDocument();
+    // City line uses the PDF issuer shape, not a raw "9494 Schaan".
+    expect(preview.getByText('Bahnhofstrasse 1 · LI-9494 Schaan / Liechtenstein')).toBeInTheDocument();
+    // Empty mobile is omitted rather than producing a doubled separator.
+    expect(preview.getByText('+41 79 123 45 67 · hello@example.com · example.com')).toBeInTheDocument();
+    expect(preview.getByText('VAT ID: CHE-123.456.789')).toBeInTheDocument();
+    expect(preview.getByText('Handelsregister Vaduz')).toBeInTheDocument();
+  });
+
+  it('explains the off state instead of showing a stale preview', async () => {
+    profileFixture = { ...baseProfile, emailSignatureEnabled: false };
+    renderPage();
+
+    expect(
+      await screen.findByText('Signature is off — emails show the logo and company name only.')
+    ).toBeInTheDocument();
+    expect(screen.queryByTestId('email-signature-preview')).not.toBeInTheDocument();
+  });
+
+  it('warns when the signature is on but every field is blank', async () => {
+    profileFixture = {
+      ...baseProfile,
+      companyName: '', addressLine1: '', addressLine2: '', postalCode: '', city: '',
+      countryCode: '', countryName: '', phone: '', mobile: '', email: '', website: '',
+      vatId: '', emailSignatureExtra: '',
+    };
+    renderPage();
+
+    expect(
+      await screen.findByText(
+        'Signature is on but every field above is blank — nothing will be added to the footer.'
+      )
+    ).toBeInTheDocument();
+  });
+
+  it('toggling off updates the preview without a save', async () => {
+    renderPage();
+    await screen.findByText('Footer preview');
+
+    await userEvent.click(screen.getByRole('switch', { name: /Show signature in email footers/i }));
+
+    expect(
+      screen.getByText('Signature is off — emails show the logo and company name only.')
+    ).toBeInTheDocument();
+  });
+
+  it('caps the legal line at 500 characters', async () => {
+    renderPage();
+
+    const textarea = (await screen.findByPlaceholderText(
+      'Handelsregister Vaduz FL-0002.123.456-7'
+    )) as HTMLTextAreaElement;
+    expect(textarea.maxLength).toBe(500);
+  });
+});
diff --git a/frontend/src/services/businessProfile.service.ts b/frontend/src/services/businessProfile.service.ts
index 9932ee66..91d4573a 100644
--- a/frontend/src/services/businessProfile.service.ts
+++ b/frontend/src/services/businessProfile.service.ts
@@ -94,6 +94,16 @@ export interface BusinessProfile {
    *  (migration 114). Defaults true. When off, scheduled emails send at
    *  their requested instant regardless of `businessHours`. */
   scheduledEmailFloorEnabled: boolean;
+  /** Global email footer signature master switch (migration 198). When
+   *  on, `wrapEmailHtml` appends the issuer block below — address,
+   *  contacts, VAT id and `emailSignatureExtra` — to the footer of EVERY
+   *  outgoing mail: transactional, preview, test and manual alike.
+   *  Defaults false so an upgraded install's footer is unchanged. */
+  emailSignatureEnabled: boolean;
+  /** Free-text legal line under the signature (Handelsregister /
+   *  registration number / disclaimer). Plain text, max 500 chars —
+   *  rendered escaped with newlines turned into <br>. Migration 198. */
+  emailSignatureExtra: string;
   createdAt: string;
   updatedAt: string;
 }