diff --git a/app/Livewire/Admin/Mail.php b/app/Livewire/Admin/Mail.php
new file mode 100644
index 0000000..da8c2f8
--- /dev/null
+++ b/app/Livewire/Admin/Mail.php
@@ -0,0 +1,104 @@
+<?php
+
+namespace App\Livewire\Admin;
+
+use App\Models\Mailbox;
+use App\Services\Mail\MailPurpose;
+use App\Services\Secrets\SecretCipher;
+use App\Support\Settings;
+use Livewire\Attributes\Layout;
+use Livewire\Component;
+
+/**
+ * The sending addresses, and which kind of mail leaves from which.
+ *
+ * The server sits at the top because there is one of it; the mailboxes are a
+ * list because there are several; the mapping is last because it only makes
+ * sense once both exist.
+ *
+ * The test-send button is a later task's job. This page only shows and edits
+ * what already exists — a button that cannot actually test is a promise the
+ * page does not keep (the same reasoning the secrets page already applies).
+ */
+#[Layout('layouts.admin')]
+class Mail extends Component
+{
+    public string $host = '';
+
+    public int|string $port = 587;
+
+    public string $encryption = 'tls';
+
+    /** @var array<string, string> purpose => mailbox key */
+    public array $purposes = [];
+
+    /**
+     * Whether credentials can be stored at all on this installation.
+     *
+     * Public so the page can say it rather than throwing on the first password
+     * a mailbox tries to decrypt — the same courtesy the secrets page already
+     * extends. A missing SECRETS_KEY is a setup state, not an error.
+     */
+    public bool $usable = true;
+
+    public function mount(): void
+    {
+        $this->authorize('mail.manage');
+
+        $this->host = (string) Settings::get('mail.host', '');
+        $this->port = (int) Settings::get('mail.port', 587);
+        $this->encryption = (string) Settings::get('mail.encryption', 'tls');
+
+        foreach (MailPurpose::ALL as $purpose) {
+            $this->purposes[$purpose] = (string) Settings::get(MailPurpose::settingKey($purpose), '');
+        }
+    }
+
+    public function saveServer(): void
+    {
+        $this->authorize('mail.manage');
+
+        // Rules on the ACTION, not on the property: a #[Validate] attribute on
+        // a Livewire property applies class-wide, and savePurposes() below
+        // would drag these along.
+        $this->validate([
+            'host' => ['required', 'string', 'max:255'],
+            'port' => ['required', 'integer', 'min:1', 'max:65535'],
+            'encryption' => ['required', 'in:tls,ssl,none'],
+        ]);
+
+        Settings::set('mail.host', $this->host);
+        Settings::set('mail.port', (int) $this->port);
+        Settings::set('mail.encryption', $this->encryption);
+
+        $this->dispatch('notify', message: __('mail_settings.server_saved'));
+    }
+
+    public function savePurposes(): void
+    {
+        $this->authorize('mail.manage');
+
+        // system is the fallback, so it is the one that may not be empty —
+        // there is nothing left to fall back to.
+        $this->validate(
+            ['purposes.system' => ['required', 'string']],
+            ['purposes.system.required' => __('mail_settings.system_required')],
+        );
+
+        foreach (MailPurpose::ALL as $purpose) {
+            Settings::set(MailPurpose::settingKey($purpose), $this->purposes[$purpose] ?? '');
+        }
+
+        $this->dispatch('notify', message: __('mail_settings.purposes_saved'));
+    }
+
+    public function render()
+    {
+        $this->usable = app(SecretCipher::class)->isUsable();
+
+        return view('livewire.admin.mail', [
+            'mailboxes' => Mailbox::query()->orderBy('key')->get(),
+            'purposeList' => MailPurpose::ALL,
+        ]);
+    }
+}
diff --git a/app/Livewire/EditMailbox.php b/app/Livewire/EditMailbox.php
new file mode 100644
index 0000000..71f8557
--- /dev/null
+++ b/app/Livewire/EditMailbox.php
@@ -0,0 +1,87 @@
+<?php
+
+namespace App\Livewire;
+
+use App\Models\Mailbox;
+use LivewireUI\Modal\ModalComponent;
+
+/**
+ * Editing a mailbox, in a modal (R20).
+ *
+ * A modal is reachable WITHOUT the page's route middleware, so it authorises
+ * itself and re-reads the record instead of trusting a property the browser
+ * hydrated. save() re-authorises independently of mount() for the same reason
+ * Secrets::guard() checks on every action rather than once: a Livewire action
+ * is reachable by anyone who can post to /livewire/update, and a mount that
+ * succeeded earlier in the session proves nothing about the request now.
+ */
+class EditMailbox extends ModalComponent
+{
+    public string $uuid = '';
+
+    public string $address = '';
+
+    public string $displayName = '';
+
+    public string $username = '';
+
+    /** Always starts empty: a stored password never travels to the browser. */
+    public string $password = '';
+
+    public bool $noReply = false;
+
+    public bool $active = true;
+
+    public function mount(string $uuid): void
+    {
+        $this->authorize('mail.manage');
+
+        $box = Mailbox::query()->where('uuid', $uuid)->firstOrFail();
+
+        $this->uuid = $box->uuid;
+        $this->address = $box->address;
+        $this->displayName = (string) $box->display_name;
+        $this->username = (string) $box->username;
+        $this->noReply = $box->no_reply;
+        $this->active = $box->active;
+    }
+
+    public function save(): void
+    {
+        $this->authorize('mail.manage');
+
+        $this->validate([
+            'address' => ['required', 'email', 'max:255'],
+            'displayName' => ['nullable', 'string', 'max:255'],
+            'username' => ['nullable', 'string', 'max:255'],
+            'password' => ['nullable', 'string', 'max:255'],
+        ]);
+
+        $box = Mailbox::query()->where('uuid', $this->uuid)->firstOrFail();
+
+        $box->address = $this->address;
+        $box->display_name = $this->displayName ?: null;
+        $box->username = $this->username ?: null;
+        $box->no_reply = $this->noReply;
+        $box->active = $this->active;
+
+        // Empty means "leave it alone", not "delete it" — otherwise every edit
+        // of an address would silently drop the password.
+        if ($this->password !== '') {
+            $box->password = $this->password;
+            $box->last_verified_at = null;
+        }
+
+        $box->save();
+
+        $this->password = '';
+        $this->dispatch('notify', message: __('mail_settings.saved'));
+        $this->dispatch('mailbox-saved');
+        $this->closeModal();
+    }
+
+    public function render()
+    {
+        return view('livewire.edit-mailbox');
+    }
+}
diff --git a/app/Support/Navigation.php b/app/Support/Navigation.php
index 7b5ea8f..93b136b 100644
--- a/app/Support/Navigation.php
+++ b/app/Support/Navigation.php
@@ -52,6 +52,7 @@ final class Navigation
                 ['admin.revenue', 'trending-up', 'revenue', null],
             ]],
             ['label' => __('admin.nav_group.system'), 'items' => [
+                ['admin.mail', 'mail', 'mail', 'mail.manage'],
                 ['admin.secrets', 'lock', 'secrets', 'secrets.manage'],
                 ['admin.settings', 'settings', 'settings', null],
             ]],
diff --git a/database/migrations/2026_07_28_110000_add_mail_manage_permission.php b/database/migrations/2026_07_28_110000_add_mail_manage_permission.php
new file mode 100644
index 0000000..c5c417d
--- /dev/null
+++ b/database/migrations/2026_07_28_110000_add_mail_manage_permission.php
@@ -0,0 +1,36 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Spatie\Permission\Models\Permission;
+use Spatie\Permission\Models\Role;
+use Spatie\Permission\PermissionRegistrar;
+
+/**
+ * Its own capability, not secrets.manage.
+ *
+ * Whoever keeps the support sender working does not thereby need the Stripe key
+ * and the DNS token. Splitting it is the difference between "can change an
+ * address" and "can move money".
+ */
+return new class extends Migration
+{
+    public function up(): void
+    {
+        app(PermissionRegistrar::class)->forgetCachedPermissions();
+
+        $permission = Permission::findOrCreate('mail.manage', 'web');
+
+        foreach (['Owner', 'Admin', 'Support'] as $role) {
+            Role::findByName($role, 'web')->givePermissionTo($permission);
+        }
+
+        app(PermissionRegistrar::class)->forgetCachedPermissions();
+    }
+
+    public function down(): void
+    {
+        app(PermissionRegistrar::class)->forgetCachedPermissions();
+        Permission::where('name', 'mail.manage')->where('guard_name', 'web')->delete();
+        app(PermissionRegistrar::class)->forgetCachedPermissions();
+    }
+};
diff --git a/lang/de/admin.php b/lang/de/admin.php
index d1ebd1e..36d66f7 100644
--- a/lang/de/admin.php
+++ b/lang/de/admin.php
@@ -21,6 +21,7 @@ return [
         'maintenance' => 'Wartungen',
         'vpn' => 'VPN',
         'revenue' => 'Umsatz',
+        'mail' => 'E-Mail',
         'secrets' => 'Zugangsdaten',
         'settings' => 'Einstellungen',
     ],
diff --git a/lang/de/mail_settings.php b/lang/de/mail_settings.php
new file mode 100644
index 0000000..486ddf1
--- /dev/null
+++ b/lang/de/mail_settings.php
@@ -0,0 +1,44 @@
+<?php
+
+return [
+    'title' => 'E-Mail',
+    'subtitle' => 'Absenderadressen und der Server, über den sie verschickt werden.',
+
+    'no_key' => 'SECRETS_KEY ist auf diesem Server nicht gesetzt. Ohne eigenen Schlüssel werden hier keine Postfach-Passwörter gespeichert — bewusst, denn APP_KEY wird routinemäßig gewechselt.',
+
+    'server_title' => 'Mailserver',
+    'server_hint' => 'Gilt für alle Postfächer — sie liegen auf demselben Server.',
+    'host' => 'Server',
+    'port' => 'Port',
+    'encryption' => 'Verschlüsselung',
+    'encryption_none' => 'Keine',
+    'save' => 'Speichern',
+    'server_saved' => 'Serverdaten gespeichert.',
+
+    'boxes_title' => 'Postfächer',
+    'address' => 'Adresse',
+    'display_name' => 'Anzeigename',
+    'username' => 'SMTP-Benutzer',
+    'username_hint' => 'Leer lassen, wenn er der Adresse entspricht.',
+    'password' => 'Passwort',
+    'password_hint' => 'Wird verschlüsselt gespeichert und nie wieder vollständig angezeigt. Leer lassen, um das bisherige zu behalten.',
+    'no_reply' => 'Keine Antworten (kein Reply-To)',
+    'no_reply_hint' => 'Ein „no-reply", auf das man antworten kann, ist eine Lüge im Absender.',
+    'active' => 'Aktiv',
+    'edit' => 'Bearbeiten',
+    'saved' => 'Postfach gespeichert.',
+    'never_verified' => 'Noch nicht bestätigt',
+    'last_verified' => 'Zuletzt bestätigt',
+
+    'purposes_title' => 'Wer verschickt was',
+    'purposes_hint' => 'Ein Zweck ohne Postfach verschickt über „System".',
+    'purpose' => [
+        'maintenance' => 'Wartungsankündigungen',
+        'provisioning' => 'Bereitstellung und Bestellbestätigung',
+        'support' => 'Antworten auf Support-Anfragen',
+        'billing' => 'Rechnungen und Zahlungserinnerungen',
+        'system' => 'System (Rückfall für alles Übrige)',
+    ],
+    'purposes_saved' => 'Zuordnung gespeichert.',
+    'system_required' => '„System" muss ein Postfach haben — es ist der Rückfall für alle anderen.',
+];
diff --git a/lang/en/admin.php b/lang/en/admin.php
index b624c01..437f973 100644
--- a/lang/en/admin.php
+++ b/lang/en/admin.php
@@ -21,6 +21,7 @@ return [
         'maintenance' => 'Maintenance',
         'vpn' => 'VPN',
         'revenue' => 'Revenue',
+        'mail' => 'Email',
         'secrets' => 'Credentials',
         'settings' => 'Settings',
     ],
diff --git a/lang/en/mail_settings.php b/lang/en/mail_settings.php
new file mode 100644
index 0000000..a91df3d
--- /dev/null
+++ b/lang/en/mail_settings.php
@@ -0,0 +1,44 @@
+<?php
+
+return [
+    'title' => 'Email',
+    'subtitle' => 'Sending addresses, and the server they go out through.',
+
+    'no_key' => 'SECRETS_KEY is not set on this server. Without a key of its own, no mailbox passwords are stored here — deliberately, because APP_KEY is rotated as routine maintenance.',
+
+    'server_title' => 'Mail server',
+    'server_hint' => 'Applies to every mailbox — they all sit on the same server.',
+    'host' => 'Server',
+    'port' => 'Port',
+    'encryption' => 'Encryption',
+    'encryption_none' => 'None',
+    'save' => 'Save',
+    'server_saved' => 'Server settings saved.',
+
+    'boxes_title' => 'Mailboxes',
+    'address' => 'Address',
+    'display_name' => 'Display name',
+    'username' => 'SMTP user',
+    'username_hint' => 'Leave empty if it matches the address.',
+    'password' => 'Password',
+    'password_hint' => 'Stored encrypted and never shown in full again. Leave empty to keep the current one.',
+    'no_reply' => 'No replies (no Reply-To)',
+    'no_reply_hint' => 'A "no-reply" that can be replied to is a lie in the sender.',
+    'active' => 'Active',
+    'edit' => 'Edit',
+    'saved' => 'Mailbox saved.',
+    'never_verified' => 'Not yet verified',
+    'last_verified' => 'Last verified',
+
+    'purposes_title' => 'Who sends what',
+    'purposes_hint' => 'A purpose with no mailbox sends through "System".',
+    'purpose' => [
+        'maintenance' => 'Maintenance announcements',
+        'provisioning' => 'Provisioning and order confirmation',
+        'support' => 'Replies to support requests',
+        'billing' => 'Invoices and payment reminders',
+        'system' => 'System (fallback for everything else)',
+    ],
+    'purposes_saved' => 'Mapping saved.',
+    'system_required' => '"System" must have a mailbox — it is the fallback for all the others.',
+];
diff --git a/resources/views/components/ui/icon.blade.php b/resources/views/components/ui/icon.blade.php
index 7e9c586..9ec707c 100644
--- a/resources/views/components/ui/icon.blade.php
+++ b/resources/views/components/ui/icon.blade.php
@@ -38,6 +38,7 @@
         'pencil'       => '<path d="M21.174 6.812a1 1 0 0 0-3.986-3.987L3.842 16.174a2 2 0 0 0-.5.83l-1.321 4.352a.5.5 0 0 0 .623.622l4.353-1.32a2 2 0 0 0 .83-.497z"/><path d="m15 5 4 4"/>',
         'trash-2'      => '<path d="M3 6h18"/><path d="M19 6v14a2 2 0 0 1-2 2H7a2 2 0 0 1-2-2V6m3 0V4a2 2 0 0 1 2-2h4a2 2 0 0 1 2 2v2"/><line x1="10" x2="10" y1="11" y2="17"/><line x1="14" x2="14" y1="11" y2="17"/>',
         'settings'     => '<path d="M12.22 2h-.44a2 2 0 0 0-2 2v.18a2 2 0 0 1-1 1.73l-.43.25a2 2 0 0 1-2 0l-.15-.08a2 2 0 0 0-2.73.73l-.22.38a2 2 0 0 0 .73 2.73l.15.1a2 2 0 0 1 1 1.72v.51a2 2 0 0 1-1 1.74l-.15.09a2 2 0 0 0-.73 2.73l.22.38a2 2 0 0 0 2.73.73l.15-.08a2 2 0 0 1 2 0l.43.25a2 2 0 0 1 1 1.73V20a2 2 0 0 0 2 2h.44a2 2 0 0 0 2-2v-.18a2 2 0 0 1 1-1.73l.43-.25a2 2 0 0 1 2 0l.15.08a2 2 0 0 0 2.73-.73l.22-.39a2 2 0 0 0-.73-2.73l-.15-.08a2 2 0 0 1-1-1.74v-.5a2 2 0 0 1 1-1.74l.15-.09a2 2 0 0 0 .73-2.73l-.22-.38a2 2 0 0 0-2.73-.73l-.15.08a2 2 0 0 1-2 0l-.43-.25a2 2 0 0 1-1-1.73V4a2 2 0 0 0-2-2z"/><circle cx="12" cy="12" r="3"/>',
+        'mail'         => '<rect width="20" height="16" x="2" y="4" rx="2"/><path d="m22 7-8.97 5.7a1.94 1.94 0 0 1-2.06 0L2 7"/>',
     ];
     $body = $icons[$name] ?? '';
 
diff --git a/resources/views/livewire/admin/mail.blade.php b/resources/views/livewire/admin/mail.blade.php
new file mode 100644
index 0000000..2ed068b
--- /dev/null
+++ b/resources/views/livewire/admin/mail.blade.php
@@ -0,0 +1,100 @@
+<div class="mx-auto max-w-3xl space-y-6">
+    <div class="animate-rise">
+        <h1 class="text-2xl font-bold tracking-tight text-ink">{{ __('mail_settings.title') }}</h1>
+        <p class="mt-1 text-sm text-muted">{{ __('mail_settings.subtitle') }}</p>
+    </div>
+
+    @if (! $usable)
+        <x-ui.alert variant="warning">{{ __('mail_settings.no_key') }}</x-ui.alert>
+    @endif
+
+    {{-- 1. The server. One of it, so one card. --}}
+    <x-ui.card>
+        <h2 class="text-lg font-semibold text-ink">{{ __('mail_settings.server_title') }}</h2>
+        <p class="mt-1 text-sm text-muted">{{ __('mail_settings.server_hint') }}</p>
+
+        <div class="mt-5 grid gap-4 sm:grid-cols-3">
+            <x-ui.input name="host" wire:model="host" :label="__('mail_settings.host')" />
+            <x-ui.input name="port" type="number" wire:model="port" :label="__('mail_settings.port')" />
+            <div>
+                <label for="encryption" class="text-sm font-medium text-ink">{{ __('mail_settings.encryption') }}</label>
+                <select id="encryption" wire:model="encryption"
+                        class="mt-1.5 w-full rounded-md border border-line-strong bg-surface px-3 py-2 text-sm text-body">
+                    <option value="tls">TLS</option>
+                    <option value="ssl">SSL</option>
+                    <option value="none">{{ __('mail_settings.encryption_none') }}</option>
+                </select>
+                @error('encryption')<p class="mt-1 text-xs text-danger">{{ $message }}</p>@enderror
+            </div>
+        </div>
+
+        <x-ui.button wire:click="saveServer" variant="primary" size="md" class="mt-5">
+            {{ __('mail_settings.save') }}
+        </x-ui.button>
+    </x-ui.card>
+
+    {{-- 2. The mailboxes. NO input field inside a <td> — R20. --}}
+    <x-ui.card>
+        <h2 class="text-lg font-semibold text-ink">{{ __('mail_settings.boxes_title') }}</h2>
+
+        <table class="mt-5 w-full text-sm">
+            <thead>
+                <tr class="border-b border-line text-left">
+                    <th class="lbl pb-2">{{ __('mail_settings.address') }}</th>
+                    <th class="lbl pb-2">{{ __('mail_settings.last_verified') }}</th>
+                    <th class="lbl pb-2"></th>
+                </tr>
+            </thead>
+            <tbody>
+                @foreach ($mailboxes as $box)
+                    <tr wire:key="mailbox-{{ $box->uuid }}" class="border-b border-line last:border-0">
+                        <td class="py-3">
+                            <span class="font-medium text-ink">{{ $box->address }}</span>
+                            <span class="ml-2 text-muted">{{ $box->key }}</span>
+                        </td>
+                        <td class="py-3 text-muted">
+                            {{ $box->last_verified_at?->local()->isoFormat('DD.MM.YYYY HH:mm') ?? __('mail_settings.never_verified') }}
+                        </td>
+                        <td class="py-3 text-right">
+                            {{-- Edit only (R18: icon beside its text, single line).
+                                 The test-send button belongs to a later task —
+                                 shipping one that cannot yet test anything is a
+                                 promise this page does not keep. --}}
+                            <x-ui.button size="sm" variant="ghost"
+                                x-on:click="$dispatch('openModal', { component: 'edit-mailbox', arguments: { uuid: '{{ $box->uuid }}' } })">
+                                <x-ui.icon name="pencil" class="size-4" />{{ __('mail_settings.edit') }}
+                            </x-ui.button>
+                        </td>
+                    </tr>
+                @endforeach
+            </tbody>
+        </table>
+    </x-ui.card>
+
+    {{-- 3. The mapping. One <select> per row — R20's stated exception. --}}
+    <x-ui.card>
+        <h2 class="text-lg font-semibold text-ink">{{ __('mail_settings.purposes_title') }}</h2>
+        <p class="mt-1 text-sm text-muted">{{ __('mail_settings.purposes_hint') }}</p>
+
+        <div class="mt-5 space-y-3">
+            @foreach ($purposeList as $purpose)
+                <div class="flex items-center justify-between gap-6 border-b border-line py-2">
+                    <span class="text-sm text-ink">{{ __('mail_settings.purpose.'.$purpose) }}</span>
+                    <select wire:model="purposes.{{ $purpose }}"
+                            class="w-64 rounded-md border border-line-strong bg-surface px-3 py-2 text-sm text-body">
+                        <option value="">—</option>
+                        @foreach ($mailboxes as $box)
+                            <option value="{{ $box->key }}">{{ $box->address }}</option>
+                        @endforeach
+                    </select>
+                </div>
+            @endforeach
+        </div>
+
+        @error('purposes.system')<p class="mt-3 text-xs text-danger">{{ $message }}</p>@enderror
+
+        <x-ui.button wire:click="savePurposes" variant="primary" size="md" class="mt-5">
+            {{ __('mail_settings.save') }}
+        </x-ui.button>
+    </x-ui.card>
+</div>
diff --git a/resources/views/livewire/edit-mailbox.blade.php b/resources/views/livewire/edit-mailbox.blade.php
new file mode 100644
index 0000000..40b6a90
--- /dev/null
+++ b/resources/views/livewire/edit-mailbox.blade.php
@@ -0,0 +1,27 @@
+<div class="rounded-lg bg-surface p-6">
+    <h3 class="text-base font-semibold text-ink">{{ __('mail_settings.edit') }}</h3>
+
+    <div class="mt-4 space-y-4">
+        <x-ui.input name="address" type="email" wire:model="address" :label="__('mail_settings.address')" />
+
+        <x-ui.input name="displayName" wire:model="displayName" :label="__('mail_settings.display_name')" />
+
+        <x-ui.input name="username" wire:model="username"
+                    :label="__('mail_settings.username')" :hint="__('mail_settings.username_hint')" />
+
+        <x-ui.input name="password" type="password" autocomplete="off" wire:model="password"
+                    :label="__('mail_settings.password')" :hint="__('mail_settings.password_hint')" />
+
+        <div class="space-y-2 rounded-lg border border-line bg-surface-2 p-4">
+            <x-ui.checkbox name="noReply" wire:model="noReply" :label="__('mail_settings.no_reply')" />
+            <p class="pl-7 text-xs text-muted">{{ __('mail_settings.no_reply_hint') }}</p>
+
+            <x-ui.checkbox name="active" wire:model="active" :label="__('mail_settings.active')" />
+        </div>
+    </div>
+
+    <div class="mt-6 flex justify-end gap-3">
+        <x-ui.button variant="secondary" x-on:click="Livewire.dispatch('closeModal')">{{ __('common.cancel') }}</x-ui.button>
+        <x-ui.button variant="primary" wire:click="save" wire:loading.attr="disabled" wire:target="save">{{ __('mail_settings.save') }}</x-ui.button>
+    </div>
+</div>
diff --git a/routes/admin.php b/routes/admin.php
index 79bfce7..e692fd1 100644
--- a/routes/admin.php
+++ b/routes/admin.php
@@ -36,6 +36,7 @@ Route::get('/provisioning', Admin\Provisioning::class)->name('provisioning');
 Route::get('/maintenance', Admin\Maintenance::class)->name('maintenance');
 Route::get('/vpn', Admin\Vpn::class)->name('vpn');
 Route::get('/revenue', Admin\Revenue::class)->name('revenue');
+Route::get('/mail', Admin\Mail::class)->name('mail');
 Route::get('/secrets', Admin\Secrets::class)->name('secrets');
 Route::get('/settings', Admin\Settings::class)->name('settings');
 
diff --git a/tests/Feature/Mail/MailSettingsPageTest.php b/tests/Feature/Mail/MailSettingsPageTest.php
new file mode 100644
index 0000000..4b41900
--- /dev/null
+++ b/tests/Feature/Mail/MailSettingsPageTest.php
@@ -0,0 +1,280 @@
+<?php
+
+use App\Livewire\Admin\Mail as MailPage;
+use App\Livewire\EditMailbox;
+use App\Models\Mailbox;
+use App\Models\User;
+use App\Services\Mail\MailPurpose;
+use App\Support\Settings;
+use Livewire\Livewire;
+
+beforeEach(function () {
+    config()->set('admin_access.secrets_key', 'base64:'.base64_encode(random_bytes(32)));
+
+    // Blank slate, not the migration's seeded five: every other file in this
+    // directory does the same (see tests/Pest.php). Two of the tests below
+    // pin a mailbox to the key 'support' and another to 'no-reply' — both
+    // collide with mailboxes.key's unique constraint against the seeded
+    // baseline RefreshDatabase leaves in place. Clearing keeps this file
+    // deterministic regardless of what the seed migration happens to contain.
+    clearMailboxSeed();
+});
+
+it('is closed to an operator without mail.manage', function () {
+    $user = User::factory()->operator('Read-only')->create();
+
+    Livewire::actingAs($user)->test(MailPage::class)->assertForbidden();
+});
+
+it('opens for an operator who has it', function () {
+    $user = User::factory()->operator('Owner')->create();
+
+    Livewire::actingAs($user)->test(MailPage::class)->assertOk()->assertSet('usable', true);
+});
+
+it('grants mail.manage to Admin and Support as well as Owner', function () {
+    // The migration hands the capability to three roles, not one. Nothing
+    // above proves the other two actually received it — an Owner-only test
+    // would stay green even if the migration's role loop silently lost a name.
+    expect(User::factory()->operator('Admin')->create()->can('mail.manage'))->toBeTrue()
+        ->and(User::factory()->operator('Support')->create()->can('mail.manage'))->toBeTrue();
+});
+
+it('is not opened by secrets.manage alone — that is the point of splitting them', function () {
+    // Billing holds secrets-adjacent capabilities but has no business changing
+    // the support sender, and vice versa. If this ever passes, the two
+    // capabilities have quietly been merged again.
+    $user = User::factory()->operator('Billing')->create();
+
+    expect($user->can('mail.manage'))->toBeFalse();
+
+    Livewire::actingAs($user)->test(MailPage::class)->assertForbidden();
+});
+
+it('edits a mailbox in a modal, never in the row (R20)', function () {
+    $box = Mailbox::factory()->create(['key' => 'support']);
+
+    $blade = file_get_contents(resource_path('views/livewire/admin/mail.blade.php'));
+
+    expect($blade)->not->toMatch('/<td[^>]*>(?:(?!<\/td>).)*<input/s')
+        ->and($blade)->toContain('openModal');
+
+    Livewire::actingAs(User::factory()->operator('Owner')->create())
+        ->test(EditMailbox::class, ['uuid' => $box->uuid])
+        ->set('address', 'neu@clupilot.com')
+        ->call('save');
+
+    expect($box->fresh()->address)->toBe('neu@clupilot.com');
+});
+
+it('never hands a stored password back to the browser', function () {
+    $box = Mailbox::factory()->create(['password' => 'streng-geheim']);
+
+    Livewire::actingAs(User::factory()->operator('Owner')->create())
+        ->test(EditMailbox::class, ['uuid' => $box->uuid])
+        ->assertSet('password', '')
+        ->assertDontSee('streng-geheim');
+});
+
+it('keeps the old password when the field is left empty', function () {
+    $box = Mailbox::factory()->create(['password' => 'bleibt']);
+
+    Livewire::actingAs(User::factory()->operator('Owner')->create())
+        ->test(EditMailbox::class, ['uuid' => $box->uuid])
+        ->set('address', 'neu@clupilot.com')
+        ->call('save');
+
+    expect($box->fresh()->password)->toBe('bleibt');
+});
+
+it('says so when SECRETS_KEY is missing, instead of crashing on the first password', function () {
+    config()->set('admin_access.secrets_key', '');
+
+    Livewire::actingAs(User::factory()->operator('Owner')->create())
+        ->test(MailPage::class)
+        ->assertOk()
+        ->assertSet('usable', false)
+        ->assertSee(__('mail_settings.no_key'));
+});
+
+it('refuses to leave the system purpose empty, because it is the fallback', function () {
+    Mailbox::factory()->create(['key' => 'no-reply']);
+    Settings::set(MailPurpose::settingKey(MailPurpose::SYSTEM), 'no-reply');
+
+    Livewire::actingAs(User::factory()->operator('Owner')->create())
+        ->test(MailPage::class)
+        ->set('purposes.system', '')
+        ->call('savePurposes')
+        ->assertHasErrors('purposes.system');
+
+    expect(Settings::get(MailPurpose::settingKey(MailPurpose::SYSTEM)))->toBe('no-reply');
+});
+
+// --- Coverage beyond the brief's list: behaviours the page and modal claim
+// but the tests above never exercise. Each was verified to fail for the
+// right reason before the implementation existed, and again by mutation
+// afterwards (see the task report).
+
+it('lists every mailbox on the page', function () {
+    Mailbox::factory()->create(['key' => 'support', 'address' => 'support@clupilot.com']);
+
+    Livewire::actingAs(User::factory()->operator('Owner')->create())
+        ->test(MailPage::class)
+        ->assertSee('support@clupilot.com')
+        ->assertSee('support');
+});
+
+it('shows the currently configured mailbox for each purpose', function () {
+    Mailbox::factory()->create(['key' => 'support']);
+    Settings::set(MailPurpose::settingKey(MailPurpose::SUPPORT), 'support');
+
+    Livewire::actingAs(User::factory()->operator('Owner')->create())
+        ->test(MailPage::class)
+        ->assertSet('purposes.support', 'support');
+});
+
+it('saves the mail server settings', function () {
+    Livewire::actingAs(User::factory()->operator('Owner')->create())
+        ->test(MailPage::class)
+        ->set('host', 'smtp.example.com')
+        ->set('port', 2525)
+        ->set('encryption', 'ssl')
+        ->call('saveServer')
+        ->assertHasNoErrors();
+
+    expect(Settings::get('mail.host'))->toBe('smtp.example.com')
+        ->and(Settings::get('mail.port'))->toBe(2525)
+        ->and(Settings::get('mail.encryption'))->toBe('ssl');
+});
+
+it('rejects an empty mail server host', function () {
+    Livewire::actingAs(User::factory()->operator('Owner')->create())
+        ->test(MailPage::class)
+        ->set('host', '')
+        ->call('saveServer')
+        ->assertHasErrors('host');
+});
+
+it('saves the purpose-to-mailbox mapping', function () {
+    Mailbox::factory()->create(['key' => 'support']);
+    Mailbox::factory()->create(['key' => 'no-reply']);
+
+    Livewire::actingAs(User::factory()->operator('Owner')->create())
+        ->test(MailPage::class)
+        ->set('purposes.system', 'no-reply')
+        ->set('purposes.support', 'support')
+        ->call('savePurposes')
+        ->assertHasNoErrors();
+
+    expect(Settings::get(MailPurpose::settingKey(MailPurpose::SUPPORT)))->toBe('support')
+        ->and(Settings::get(MailPurpose::settingKey(MailPurpose::SYSTEM)))->toBe('no-reply');
+});
+
+it('re-checks mail.manage on every page action, not only at mount', function () {
+    // mount() alone would pass every test above: an Owner has the capability
+    // for the whole test, so nothing so far proves saveServer()/savePurposes()
+    // carry their own authorize() rather than relying on mount() having run
+    // once. Swap the authenticated user between mount and the action — same
+    // shape as SecretsPageTest's "refuses every action while locked", applied
+    // to the capability gate instead of the password gate.
+    $owner = User::factory()->operator('Owner')->create();
+    $billing = User::factory()->operator('Billing')->create();
+
+    // A fresh mount per action, like SecretsPageTest's equivalent: a 403
+    // response carries no usable Livewire snapshot, so a second ->call() on
+    // the same already-forbidden instance fails on the snapshot itself
+    // rather than on the authorization this test means to check.
+    foreach (['saveServer', 'savePurposes'] as $action) {
+        $page = Livewire::actingAs($owner)->test(MailPage::class)->assertOk();
+
+        Livewire::actingAs($billing);
+
+        $page->call($action)->assertForbidden();
+    }
+});
+
+it('re-checks mail.manage on modal save, not only at mount', function () {
+    // Same gap as above, for the modal: mount() re-reads the record instead of
+    // trusting the browser (R20), but that is a different guarantee from
+    // save() re-authorising instead of trusting a mount that already happened.
+    $box = Mailbox::factory()->create(['key' => 'support']);
+    $owner = User::factory()->operator('Owner')->create();
+    $billing = User::factory()->operator('Billing')->create();
+
+    $modal = Livewire::actingAs($owner)->test(EditMailbox::class, ['uuid' => $box->uuid])->assertOk();
+
+    Livewire::actingAs($billing);
+
+    $modal->set('address', 'neu@clupilot.com')->call('save')->assertForbidden();
+});
+
+it('refuses to edit a mailbox without mail.manage, even though the modal bypasses the page route', function () {
+    $box = Mailbox::factory()->create(['key' => 'support']);
+
+    Livewire::actingAs(User::factory()->operator('Billing')->create())
+        ->test(EditMailbox::class, ['uuid' => $box->uuid])
+        ->assertForbidden();
+});
+
+it('updates the password when a new one is entered', function () {
+    // The mirror of "keeps the old password when the field is left empty":
+    // that test alone would stay green even if save() stopped writing the
+    // password entirely, since "never changes" also satisfies "kept the old
+    // one". This proves the other half — a new value actually lands.
+    $box = Mailbox::factory()->create(['password' => 'alt']);
+
+    Livewire::actingAs(User::factory()->operator('Owner')->create())
+        ->test(EditMailbox::class, ['uuid' => $box->uuid])
+        ->set('password', 'neu-und-sicher')
+        ->call('save');
+
+    expect($box->fresh()->password)->toBe('neu-und-sicher');
+});
+
+it('clears last_verified_at when the password changes, since it no longer proves anything', function () {
+    $box = Mailbox::factory()->create(['password' => 'alt', 'last_verified_at' => now()]);
+
+    Livewire::actingAs(User::factory()->operator('Owner')->create())
+        ->test(EditMailbox::class, ['uuid' => $box->uuid])
+        ->set('password', 'neu-und-sicher')
+        ->call('save');
+
+    expect($box->fresh()->last_verified_at)->toBeNull();
+});
+
+it('saves display name, username, no-reply and active together', function () {
+    $box = Mailbox::factory()->create(['no_reply' => false, 'active' => true]);
+
+    Livewire::actingAs(User::factory()->operator('Owner')->create())
+        ->test(EditMailbox::class, ['uuid' => $box->uuid])
+        ->set('displayName', 'Support-Team')
+        ->set('username', 'smtp-user')
+        ->set('noReply', true)
+        ->set('active', false)
+        ->call('save');
+
+    $box->refresh();
+
+    expect($box->display_name)->toBe('Support-Team')
+        ->and($box->username)->toBe('smtp-user')
+        ->and($box->no_reply)->toBeTrue()
+        ->and($box->active)->toBeFalse();
+});
+
+it('pre-fills the form from the existing record', function () {
+    $box = Mailbox::factory()->create([
+        'address' => 'support@clupilot.com',
+        'display_name' => 'Support-Team',
+        'username' => 'smtp-support',
+        'no_reply' => true,
+        'active' => false,
+    ]);
+
+    Livewire::actingAs(User::factory()->operator('Owner')->create())
+        ->test(EditMailbox::class, ['uuid' => $box->uuid])
+        ->assertSet('address', 'support@clupilot.com')
+        ->assertSet('displayName', 'Support-Team')
+        ->assertSet('username', 'smtp-support')
+        ->assertSet('noReply', true)
+        ->assertSet('active', false);
+});