From aee8f1389999a0e00f2dbc77f99861df56ced7a0 Mon Sep 17 00:00:00 2001
From: Ronni Baslund <rhb@vdoc.dk>
Date: Sun, 7 Jun 2026 00:16:30 +0200
Subject: [PATCH] feat(mail): tenant alias and distribution-list management via
 Stalwart

Customer-admin Mail settings backed by Stalwart JMAP: per-tenant aliases
(extra addresses routing to a mailbox) and distribution lists (one address
fanning out to many recipients). Adds StalwartClient x:Alias/x:MailingList
methods, a tenant-scoped MailController/MailService, the portal Mail settings
page and its proxy routes, and the mailboxAddress field on TenantUserDoc.
Removes the old mock mail data now that the page reads live data.
---
 apps/portal/data/workspace.ts                 |  32 -
 apps/portal/pages/admin/mail.vue              | 725 +++++++-----------
 .../api/tenants/[slug]/mail/aliases.get.ts    |  13 +
 .../api/tenants/[slug]/mail/aliases.post.ts   |  16 +
 .../[slug]/mail/aliases/[address].delete.ts   |  16 +
 .../api/tenants/[slug]/mail/lists.get.ts      |  13 +
 .../api/tenants/[slug]/mail/lists.post.ts     |  16 +
 .../tenants/[slug]/mail/lists/[id].delete.ts  |  16 +
 .../tenants/[slug]/mail/lists/[id].patch.ts   |  17 +
 apps/portal/types/workspace.ts                |   3 +
 services/platform-api/src/app.module.ts       |   2 +
 .../src/integrations/stalwart.client.ts       | 184 +++++
 .../src/mail/dto/create-alias.dto.ts          |  17 +
 .../src/mail/dto/create-list.dto.ts           |  23 +
 .../src/mail/dto/update-list.dto.ts           |   9 +
 .../platform-api/src/mail/mail.controller.ts  | 125 +++
 services/platform-api/src/mail/mail.module.ts |  26 +
 .../platform-api/src/mail/mail.service.ts     | 243 ++++++
 18 files changed, 1035 insertions(+), 461 deletions(-)
 create mode 100644 apps/portal/server/api/tenants/[slug]/mail/aliases.get.ts
 create mode 100644 apps/portal/server/api/tenants/[slug]/mail/aliases.post.ts
 create mode 100644 apps/portal/server/api/tenants/[slug]/mail/aliases/[address].delete.ts
 create mode 100644 apps/portal/server/api/tenants/[slug]/mail/lists.get.ts
 create mode 100644 apps/portal/server/api/tenants/[slug]/mail/lists.post.ts
 create mode 100644 apps/portal/server/api/tenants/[slug]/mail/lists/[id].delete.ts
 create mode 100644 apps/portal/server/api/tenants/[slug]/mail/lists/[id].patch.ts
 create mode 100644 services/platform-api/src/mail/dto/create-alias.dto.ts
 create mode 100644 services/platform-api/src/mail/dto/create-list.dto.ts
 create mode 100644 services/platform-api/src/mail/dto/update-list.dto.ts
 create mode 100644 services/platform-api/src/mail/mail.controller.ts
 create mode 100644 services/platform-api/src/mail/mail.module.ts
 create mode 100644 services/platform-api/src/mail/mail.service.ts

diff --git a/apps/portal/data/workspace.ts b/apps/portal/data/workspace.ts
index a917d67..2c8caa0 100644
--- a/apps/portal/data/workspace.ts
+++ b/apps/portal/data/workspace.ts
@@ -72,38 +72,6 @@ export const sampleAudit = [
   { id: 'a8', when: '09:30:00', actor: 'Anne Baslund',    action: 'branding.color_set',   target: '#D4FF3A',            ip: '92.43.118.4',  tone: 'info' as const },
 ]
 
-// Org-wide mail aliases — strict port of platform-admin.jsx ORG_ALIASES (line 9)
-export const orgAliases = [
-  { alias: 'info@dezky.com',     dest: 'Distribution · Everyone', active: true,  created: '14 Jan 2026' },
-  { alias: 'sales@dezky.com',    dest: 'frederik@dezky.com',      active: true,  created: '22 Jan 2026' },
-  { alias: 'support@dezky.com',  dest: 'sofie@dezky.com',         active: true,  created: '22 Jan 2026' },
-  { alias: 'no-reply@dezky.com', dest: '(discard)',               active: true,  created: '14 Jan 2026' },
-  { alias: 'careers@dezky.com',  dest: 'anne@dezky.com',          active: true,  created: '04 Mar 2026' },
-  { alias: 'legal@dezky.com',    dest: 'mikkel@dezky.com',        active: false, created: '12 Apr 2026' },
-]
-
-// Forwarding rules — strict port of platform-admin.jsx FORWARDING_RULES (line 18)
-export const forwardingRules = [
-  { name: 'Out-of-hours to on-call', match: 'support@dezky.com · 18:00–08:00 CET',  fwd: 'oncall@dezky.com',  enabled: true },
-  { name: 'Vendor invoices',          match: 'subject: "invoice" · from: *@vendors', fwd: 'finance@dezky.com', enabled: true },
-  { name: 'Legal threads',            match: 'cc: legal@*',                          fwd: 'mikkel@dezky.com',  enabled: false },
-]
-
-// Distribution lists — strict port of platform-admin.jsx DISTRIBUTION_LISTS (line 24)
-export const distributionLists = [
-  { name: 'Everyone',      alias: 'everyone@dezky.com',     members: 11, owner: 'Anne Baslund',    moderation: 'open' as const,   external: false },
-  { name: 'Engineering',   alias: 'eng@dezky.com',           members: 4,  owner: 'Anne Baslund',    moderation: 'closed' as const, external: false },
-  { name: 'Leadership',    alias: 'leads@dezky.com',         members: 3,  owner: 'Anne Baslund',    moderation: 'closed' as const, external: false },
-  { name: 'Customers VIP', alias: 'vip-customers@dezky.com', members: 0,  owner: 'Frederik Madsen', moderation: 'closed' as const, external: true  },
-]
-
-// Anti-spam content filters — strict port of platform-admin.jsx ANTI_SPAM_FILTERS (line 31)
-export const antiSpamFilters = [
-  { name: 'Block executable attachments',   match: 'attachment ext in (.exe, .scr, .bat, .cmd)', action: 'reject' as const,     enabled: true },
-  { name: 'Quarantine cryptocurrency mail', match: 'body contains "wallet address"',              action: 'quarantine' as const, enabled: true },
-  { name: 'Tag external mail',              match: 'from outside @dezky.com',                     action: 'add tag' as const,    enabled: true },
-]
-
 // Full groups list — strict port of platform-admin.jsx GROUPS_FULL (line 64)
 export const groupsFull = [
   { id: 'g_eng',   name: 'Engineering', alias: 'engineering@dezky.com', members: 4,  description: 'Product engineering team',    created: '14 Jan 2026', owner: 'Anne Baslund' },
diff --git a/apps/portal/pages/admin/mail.vue b/apps/portal/pages/admin/mail.vue
index 46bb1ac..898bff6 100644
--- a/apps/portal/pages/admin/mail.vue
+++ b/apps/portal/pages/admin/mail.vue
@@ -1,112 +1,203 @@
 <script setup lang="ts">
-// Strict port of project/platform-admin.jsx `MailSettingsScreen` (lines 76-305).
-// 5 tabs: Aliases / Forwarding / Filters · anti-spam / Distribution lists /
-// Compliance · retention. Each uses the source's data and copy verbatim.
+// Mail settings. The per-tenant parts are real: Aliases (extra addresses that
+// route to a mailbox) and Distribution lists (one address → many recipients),
+// both backed by Stalwart via /api/tenants/:slug/mail/*. The other three tabs —
+// Forwarding, Filters, Compliance — are server-global in Stalwart (one shared
+// spam engine / retention policy), so they're operator-managed, not per-customer;
+// they render an honest "managed by Dezky" state rather than fake controls.
 
+import type { TenantUserDoc } from '~/types/workspace'
 
-import {
-  orgAliases,
-  forwardingRules,
-  antiSpamFilters,
-  distributionLists,
-} from '~/data/workspace'
-
-const tab = ref<'aliases' | 'forwarding' | 'filters' | 'lists' | 'compliance'>('aliases')
+interface AliasView {
+  address: string
+  localPart: string
+  domain: string
+  destination: string
+  accountId: string
+  enabled: boolean
+}
+interface ListView {
+  id: string
+  name: string
+  address: string
+  domain: string
+  recipients: string[]
+  members: number
+  description?: string
+}
+interface DomainLite { id: string; domain: string; isPrimary: boolean }
 
 const toast = useToast()
+const { tenant } = useTenant()
+const slug = computed(() => tenant.value?.slug ?? '')
+const { request } = useApiFetch()
 
-const addAliasOpen = ref(false)
-const ruleOpen = ref(false)
-const filterOpen = ref(false)
-const listOpen = ref(false)
-const holdOpen = ref(false)
-const openList = ref<typeof distributionLists[number] | null>(null)
-const deleteListOpen = ref(false)
+const tab = ref<'aliases' | 'lists' | 'forwarding' | 'filters' | 'compliance'>('aliases')
 
-// Track each forwarding rule's enabled flag locally so the toggle visually flips.
-const ruleEnabled = reactive<Record<string, boolean>>(
-  Object.fromEntries(forwardingRules.map((r) => [r.name, r.enabled])),
+const { data: aliases, refresh: refreshAliases } = await useFetch<AliasView[]>(
+  () => `/api/tenants/${slug.value}/mail/aliases`,
+  { key: 'mail-aliases', default: () => [], immediate: !!slug.value, watch: [slug] },
 )
-const filterEnabled = reactive<Record<string, boolean>>(
-  Object.fromEntries(antiSpamFilters.map((f) => [f.name, f.enabled])),
+const { data: lists, refresh: refreshLists } = await useFetch<ListView[]>(
+  () => `/api/tenants/${slug.value}/mail/lists`,
+  { key: 'mail-lists', default: () => [], immediate: !!slug.value, watch: [slug] },
+)
+const { data: domains } = await useFetch<DomainLite[]>(
+  () => `/api/tenants/${slug.value}/domains`,
+  { key: 'mail-domains', default: () => [], immediate: !!slug.value, watch: [slug] },
+)
+const { data: users } = await useFetch<TenantUserDoc[]>(
+  () => `/api/tenants/${slug.value}/users`,
+  { key: 'mail-users', default: () => [], immediate: !!slug.value, watch: [slug] },
 )
 
-async function copyAlias(alias: string) {
+const primaryDomain = computed(() => domains.value?.find((d) => d.isPrimary) ?? domains.value?.[0])
+// Only users with a real mailbox can be an alias destination.
+const mailboxUsers = computed(() => (users.value ?? []).filter((u) => !!u.mailboxAddress))
+
+function toastErr(err: unknown, title: string) {
+  const e = err as { data?: { message?: string | string[] }; message?: string }
+  const m = e?.data?.message ?? e?.message ?? 'Unknown error'
+  toast.bad(title, Array.isArray(m) ? m.join(', ') : m)
+}
+
+const tabs = computed(() => [
+  { value: 'aliases', label: 'Aliases', count: aliases.value?.length ?? 0 },
+  { value: 'lists', label: 'Distribution lists', count: lists.value?.length ?? 0 },
+  { value: 'forwarding', label: 'Forwarding' },
+  { value: 'filters', label: 'Filters · anti-spam' },
+  { value: 'compliance', label: 'Compliance · retention' },
+])
+
+// ── Aliases ──
+const aliasOpen = ref(false)
+const aliasBusy = ref(false)
+const aliasForm = reactive({ localPart: '', domain: '', destinationUserId: '' })
+const aliasDeleteTarget = ref<AliasView | null>(null)
+const aliasDeleting = ref(false)
+
+function openAlias() {
+  aliasForm.localPart = ''
+  aliasForm.domain = primaryDomain.value?.domain ?? ''
+  aliasForm.destinationUserId = mailboxUsers.value[0]?._id ?? ''
+  aliasOpen.value = true
+}
+async function submitAlias() {
+  if (!aliasForm.localPart.trim() || !aliasForm.domain || !aliasForm.destinationUserId) return
+  aliasBusy.value = true
   try {
-    await navigator.clipboard.writeText(alias)
-    toast.ok('Alias copied', alias)
-  } catch {
-    toast.warn('Copy failed', 'Select and copy manually')
+    await request(`/api/tenants/${slug.value}/mail/aliases`, { method: 'POST', body: { ...aliasForm } })
+    await refreshAliases()
+    toast.ok('Alias created')
+    aliasOpen.value = false
+  } catch (err) {
+    toastErr(err, 'Could not create alias')
+  } finally {
+    aliasBusy.value = false
+  }
+}
+async function confirmDeleteAlias() {
+  const a = aliasDeleteTarget.value
+  if (!a) return
+  aliasDeleting.value = true
+  try {
+    await request(`/api/tenants/${slug.value}/mail/aliases/${encodeURIComponent(a.address)}`, { method: 'DELETE' })
+    await refreshAliases()
+    toast.ok('Alias deleted', a.address)
+    aliasDeleteTarget.value = null
+  } catch (err) {
+    toastErr(err, 'Could not delete alias')
+  } finally {
+    aliasDeleting.value = false
+  }
+}
+function copyText(t: string) {
+  if (typeof navigator !== 'undefined' && navigator.clipboard) navigator.clipboard.writeText(t)
+  toast.ok('Copied to clipboard')
+}
+
+// ── Distribution lists ──
+const listOpen = ref(false)
+const listBusy = ref(false)
+const listForm = reactive({ localPart: '', domain: '', description: '', recipientsText: '' })
+const openList = ref<ListView | null>(null)
+const manageText = ref('')
+const manageBusy = ref(false)
+const listDeleteTarget = ref<ListView | null>(null)
+const listDeleting = ref(false)
+
+function parseRecipients(text: string): string[] {
+  return [...new Set(text.split(/[\s,;]+/).map((s) => s.trim().toLowerCase()).filter(Boolean))]
+}
+function openListCreate() {
+  listForm.localPart = ''
+  listForm.domain = primaryDomain.value?.domain ?? ''
+  listForm.description = ''
+  listForm.recipientsText = ''
+  listOpen.value = true
+}
+async function submitList() {
+  if (!listForm.localPart.trim() || !listForm.domain) return
+  listBusy.value = true
+  try {
+    await request(`/api/tenants/${slug.value}/mail/lists`, {
+      method: 'POST',
+      body: {
+        localPart: listForm.localPart.trim(),
+        domain: listForm.domain,
+        description: listForm.description.trim() || undefined,
+        recipients: parseRecipients(listForm.recipientsText),
+      },
+    })
+    await refreshLists()
+    toast.ok('List created')
+    listOpen.value = false
+  } catch (err) {
+    toastErr(err, 'Could not create list')
+  } finally {
+    listBusy.value = false
+  }
+}
+function manage(l: ListView) {
+  openList.value = l
+  manageText.value = l.recipients.join('\n')
+}
+async function saveList() {
+  const l = openList.value
+  if (!l) return
+  manageBusy.value = true
+  try {
+    await request(`/api/tenants/${slug.value}/mail/lists/${l.id}`, {
+      method: 'PATCH',
+      body: { recipients: parseRecipients(manageText.value) },
+    })
+    await refreshLists()
+    toast.ok('Members saved', l.address)
+    openList.value = null
+  } catch (err) {
+    toastErr(err, 'Could not save members')
+  } finally {
+    manageBusy.value = false
+  }
+}
+async function confirmDeleteList() {
+  const l = listDeleteTarget.value
+  if (!l) return
+  listDeleting.value = true
+  try {
+    await request(`/api/tenants/${slug.value}/mail/lists/${l.id}`, { method: 'DELETE' })
+    await refreshLists()
+    toast.ok('List deleted', l.address)
+    listDeleteTarget.value = null
+    openList.value = null
+  } catch (err) {
+    toastErr(err, 'Could not delete list')
+  } finally {
+    listDeleting.value = false
   }
 }
 
-function aliasAction(alias: string, id: string) {
-  if (id === 'edit') addAliasOpen.value = true
-  else if (id === 'copy') copyAlias(alias)
-  else if (id === 'disable') toast.info(`${alias} disabled`)
-  else if (id === 'delete') toast.bad(`${alias} deleted`)
-}
-
-const aliasItems = [
-  { id: 'edit',    label: 'Edit alias',     icon: 'brush' as const },
-  { id: 'copy',    label: 'Copy address',   icon: 'copy' as const },
-  { id: 'disable', label: 'Disable alias',  icon: 'x' as const },
-  { id: 'sep1',    separator: true },
-  { id: 'delete',  label: 'Delete alias',   icon: 'trash' as const, danger: true },
-]
-
-function ruleAction(name: string, id: string) {
-  if (id === 'edit') ruleOpen.value = true
-  else if (id === 'run') toast.info(`Running "${name}" once`)
-  else if (id === 'duplicate') toast.ok(`"${name}" duplicated`)
-  else if (id === 'delete') toast.bad(`"${name}" deleted`)
-}
-const ruleItems = [
-  { id: 'edit',      label: 'Edit rule',     icon: 'brush' as const },
-  { id: 'run',       label: 'Run once now',  icon: 'refresh' as const },
-  { id: 'duplicate', label: 'Duplicate',     icon: 'copy' as const },
-  { id: 'sep1',      separator: true },
-  { id: 'delete',    label: 'Delete rule',   icon: 'trash' as const, danger: true },
-]
-
-function filterAction(name: string, id: string) {
-  if (id === 'edit') filterOpen.value = true
-  else if (id === 'duplicate') toast.ok(`"${name}" duplicated`)
-  else if (id === 'delete') toast.bad(`"${name}" deleted`)
-}
-const filterItems = [
-  { id: 'edit',      label: 'Edit filter',   icon: 'brush' as const },
-  { id: 'duplicate', label: 'Duplicate',     icon: 'copy' as const },
-  { id: 'sep1',      separator: true },
-  { id: 'delete',    label: 'Delete filter', icon: 'trash' as const, danger: true },
-]
-
-function confirmDeleteList() {
-  deleteListOpen.value = false
-  const name = openList.value?.name
-  openList.value = null
-  toast.bad(`${name} deleted`)
-}
-
-const retention = ref<'30d' | '1year' | '3year' | 'unlimited'>('3year')
-const retentionOptions = [
-  { v: '30d' as const,       label: '30 days',                d: 'Standard retention. Anything older is permanently deleted.' },
-  { v: '1year' as const,     label: '1 year',                 d: 'Mid-term. Suitable for most non-regulated businesses.' },
-  { v: '3year' as const,     label: '3 years · recommended',  d: 'Danish bookkeeping retention compliant (5-year option also available).' },
-  { v: 'unlimited' as const, label: 'Unlimited',              d: 'Required for regulated industries (legal, healthcare, public sector).' },
-]
-
-const tabs = [
-  { value: 'aliases',    label: 'Aliases',             count: orgAliases.length },
-  { value: 'forwarding', label: 'Forwarding',          count: forwardingRules.length },
-  { value: 'filters',    label: 'Filters · anti-spam', count: antiSpamFilters.length },
-  { value: 'lists',      label: 'Distribution lists',  count: distributionLists.length },
-  { value: 'compliance', label: 'Compliance · retention' },
-]
-
-function toneFor(action: string): 'bad' | 'warn' | 'info' {
-  return action === 'reject' ? 'bad' : action === 'quarantine' ? 'warn' : 'info'
-}
+const hasDomain = computed(() => (domains.value?.length ?? 0) > 0)
 </script>
 
 <template>
@@ -114,7 +205,7 @@ function toneFor(action: string): 'bad' | 'warn' | 'info' {
     <PageHeader
       eyebrow="Workspace"
       title="Mail settings"
-      subtitle="Organization-level aliases, forwarding, content filters, and compliance policies."
+      subtitle="Aliases and distribution lists for your domains. Spam filtering and retention are managed by Dezky."
     />
     <div class="tab-wrap">
       <Tabs v-model="tab" :items="tabs" />
@@ -124,25 +215,26 @@ function toneFor(action: string): 'bad' | 'warn' | 'info' {
       <!-- ALIASES -->
       <template v-if="tab === 'aliases'">
         <div class="row">
-          <div class="lead">Aliases route mail to existing users or distribution lists. They count against your domain, not your seats.</div>
-          <UiButton variant="primary" @click="addAliasOpen = true">
+          <div class="lead">Aliases route mail to an existing mailbox. They count against your domain, not your seats.</div>
+          <UiButton variant="primary" :disabled="!hasDomain || mailboxUsers.length === 0" @click="openAlias">
             <template #leading><UiIcon name="plus" :size="14" /></template>
             Add alias
           </UiButton>
         </div>
-        <Card :pad="0">
+        <Card v-if="!hasDomain" class="notice"><UiIcon name="globe" :size="18" stroke="var(--text-mute)" /> Add a domain first to create aliases.</Card>
+        <Card v-else-if="(aliases?.length ?? 0) === 0" class="notice"><UiIcon name="mail" :size="18" stroke="var(--text-mute)" /> No aliases yet. Add one to route extra addresses to a mailbox.</Card>
+        <Card v-else :pad="0">
           <table class="tbl">
-            <thead><tr><th>Alias</th><th></th><th>Destination</th><th>State</th><th>Created</th><th></th></tr></thead>
+            <thead><tr><th>Alias</th><th></th><th>Delivers to</th><th>State</th><th></th></tr></thead>
             <tbody>
-              <tr v-for="r in orgAliases" :key="r.alias">
-                <td><Mono style="font-weight: 500">{{ r.alias }}</Mono></td>
+              <tr v-for="a in aliases" :key="a.address">
+                <td><Mono style="font-weight: 500">{{ a.address }}</Mono></td>
                 <td><UiIcon name="arrowRight" :size="12" stroke="var(--text-mute)" /></td>
-                <td>{{ r.dest }}</td>
-                <td><Badge :tone="r.active ? 'ok' : 'neutral'" dot>{{ r.active ? 'active' : 'paused' }}</Badge></td>
-                <td><Mono dim>{{ r.created }}</Mono></td>
+                <td><Mono dim>{{ a.destination }}</Mono></td>
+                <td><Badge :tone="a.enabled ? 'ok' : 'neutral'" dot>{{ a.enabled ? 'active' : 'paused' }}</Badge></td>
                 <td class="right">
-                  <UiButton size="sm" variant="ghost" @click="copyAlias(r.alias)"><UiIcon name="copy" :size="13" /></UiButton>
-                  <AdminKebabMenu :items="aliasItems" :icon-size="13" @select="(id) => aliasAction(r.alias, id)" />
+                  <UiButton size="sm" variant="ghost" @click="copyText(a.address)"><UiIcon name="copy" :size="13" /></UiButton>
+                  <UiButton size="sm" variant="ghost" @click="aliasDeleteTarget = a"><UiIcon name="trash" :size="13" /></UiButton>
                 </td>
               </tr>
             </tbody>
@@ -150,288 +242,148 @@ function toneFor(action: string): 'bad' | 'warn' | 'info' {
         </Card>
       </template>
 
-      <!-- FORWARDING -->
-      <template v-else-if="tab === 'forwarding'">
-        <div class="row">
-          <div class="lead">Conditional rules applied to all incoming mail. Useful for routing customer inquiries or auto-escalating.</div>
-          <UiButton variant="primary" @click="ruleOpen = true">
-            <template #leading><UiIcon name="plus" :size="14" /></template>
-            New rule
-          </UiButton>
-        </div>
-        <div class="rules">
-          <Card v-for="r in forwardingRules" :key="r.name" :pad="16">
-            <div class="rule-row">
-              <button class="toggle" :class="{ on: ruleEnabled[r.name] }" @click="ruleEnabled[r.name] = !ruleEnabled[r.name]"><span /></button>
-              <div class="rule-meta">
-                <div class="rule-name">{{ r.name }}</div>
-                <div class="rule-line">
-                  <Mono dim>WHEN</Mono>
-                  <span class="rule-match">{{ r.match }}</span>
-                  <UiIcon name="arrowRight" :size="11" stroke="var(--text-mute)" />
-                  <Mono dim>FORWARD TO</Mono>
-                  <Mono>{{ r.fwd }}</Mono>
-                </div>
-              </div>
-              <UiButton size="sm" variant="ghost" @click="ruleOpen = true">Edit</UiButton>
-              <AdminKebabMenu :items="ruleItems" @select="(id) => ruleAction(r.name, id)" />
-            </div>
-          </Card>
-        </div>
-      </template>
-
-      <!-- FILTERS -->
-      <template v-else-if="tab === 'filters'">
-        <div class="row">
-          <div class="lead">Org-wide content filters apply <i>before</i> user-level rules. Stalwart's spam engine handles the rest automatically.</div>
-          <UiButton variant="primary" @click="filterOpen = true">
-            <template #leading><UiIcon name="plus" :size="14" /></template>
-            New filter
-          </UiButton>
-        </div>
-        <Card :pad="0">
-          <table class="tbl">
-            <thead><tr><th>Filter</th><th>Match</th><th>Action</th><th></th></tr></thead>
-            <tbody>
-              <tr v-for="f in antiSpamFilters" :key="f.name">
-                <td>
-                  <div class="filter-name">
-                    <button class="toggle" :class="{ on: filterEnabled[f.name] }" @click="filterEnabled[f.name] = !filterEnabled[f.name]"><span /></button>
-                    <span>{{ f.name }}</span>
-                  </div>
-                </td>
-                <td><Mono dim>{{ f.match }}</Mono></td>
-                <td><Badge :tone="toneFor(f.action)">{{ f.action }}</Badge></td>
-                <td class="right"><AdminKebabMenu :items="filterItems" @select="(id) => filterAction(f.name, id)" /></td>
-              </tr>
-            </tbody>
-          </table>
-        </Card>
-        <div class="builtin">
-          <UiIcon name="shield" :size="16" stroke="var(--ok)" />
-          <div>
-            <div class="builtin-title">Built-in spam protection · enabled</div>
-            <div class="builtin-sub">
-              Stalwart's reputation engine and Bayesian filter block ~94% of spam at the edge. <Mono>last 7d: 12,840 blocked · 18 quarantined · 0 false positives reported</Mono>
-            </div>
-          </div>
-        </div>
-      </template>
-
-      <!-- LISTS -->
+      <!-- DISTRIBUTION LISTS -->
       <template v-else-if="tab === 'lists'">
         <div class="row">
-          <div class="lead">Distribution lists send mail to many recipients via a single alias. Members can be internal users, groups, or external addresses.</div>
-          <UiButton variant="primary" @click="listOpen = true">
+          <div class="lead">Distribution lists send mail to many recipients via a single address. Members can be any email address.</div>
+          <UiButton variant="primary" :disabled="!hasDomain" @click="openListCreate">
             <template #leading><UiIcon name="plus" :size="14" /></template>
             New list
           </UiButton>
         </div>
-        <div class="lists">
-          <Card v-for="l in distributionLists" :key="l.alias">
+        <Card v-if="!hasDomain" class="notice"><UiIcon name="globe" :size="18" stroke="var(--text-mute)" /> Add a domain first to create lists.</Card>
+        <Card v-else-if="(lists?.length ?? 0) === 0" class="notice"><UiIcon name="users" :size="18" stroke="var(--text-mute)" /> No distribution lists yet.</Card>
+        <div v-else class="lists">
+          <Card v-for="l in lists" :key="l.id">
             <div class="list-head">
               <div>
-                <div class="list-title">
-                  <UiIcon name="users" :size="16" stroke="var(--text-mute)" />
-                  <span class="list-name">{{ l.name }}</span>
-                  <Badge v-if="l.external" tone="warn">external members</Badge>
-                </div>
-                <Mono dim style="display: block; margin-top: 4px">{{ l.alias }}</Mono>
+                <div class="list-title"><UiIcon name="users" :size="16" stroke="var(--text-mute)" /><span class="list-name">{{ l.name }}</span></div>
+                <Mono dim style="display: block; margin-top: 4px">{{ l.address }}</Mono>
               </div>
-              <Badge :tone="l.moderation === 'open' ? 'ok' : 'neutral'">{{ l.moderation }}</Badge>
+              <Badge tone="neutral">{{ l.members }} member{{ l.members === 1 ? '' : 's' }}</Badge>
             </div>
+            <div v-if="l.description" class="list-desc">{{ l.description }}</div>
             <div class="list-row">
-              <div>
-                <Eyebrow>Members</Eyebrow>
-                <div class="list-num">{{ l.members }}</div>
-              </div>
-              <div class="list-owner">
-                <Eyebrow>Owner</Eyebrow>
-                <div>{{ l.owner }}</div>
-              </div>
-              <UiButton size="sm" variant="secondary" @click="openList = l">Manage</UiButton>
+              <UiButton size="sm" variant="secondary" @click="manage(l)">Manage members</UiButton>
+              <UiButton size="sm" variant="ghost" @click="listDeleteTarget = l"><template #leading><UiIcon name="trash" :size="13" /></template>Delete</UiButton>
             </div>
           </Card>
         </div>
       </template>
 
-      <!-- COMPLIANCE -->
+      <!-- FORWARDING / FILTERS / COMPLIANCE — platform-managed -->
       <template v-else>
-        <div class="compliance">
-          <Card>
-            <div class="card-head">
-              <Eyebrow>Retention</Eyebrow>
-              <div class="card-title">Mail retention policy</div>
-              <div class="card-sub">Applied org-wide. Compliance requirements override user-level deletion.</div>
-            </div>
-            <div class="radio-big">
-              <label v-for="o in retentionOptions" :key="o.v" :class="{ active: retention === o.v }">
-                <span class="radio-dot"><span v-if="retention === o.v" /></span>
-                <input type="radio" :value="o.v" v-model="retention" />
-                <div>
-                  <div class="radio-label">{{ o.label }}</div>
-                  <div class="radio-d">{{ o.d }}</div>
-                </div>
-              </label>
-            </div>
-          </Card>
-
-          <Card>
-            <div class="card-head card-head-inline">
-              <div>
-                <Eyebrow>Journaling</Eyebrow>
-                <div class="card-title">Mail journaling</div>
-                <div class="card-sub">Copy every inbound and outbound mail to a journal mailbox for e-discovery.</div>
-              </div>
-              <button class="toggle"><span /></button>
-            </div>
-            <div class="muted">
-              When enabled, journals are written to <Mono>journal@dezky.com</Mono>. Storage usage counts against your plan. Available on Business and Enterprise plans.
-            </div>
-          </Card>
-
-          <Card>
-            <div class="card-head card-head-inline">
-              <div>
-                <Eyebrow>Legal hold</Eyebrow>
-                <div class="card-title">Legal hold cases</div>
-              </div>
-              <UiButton size="sm" variant="secondary" @click="holdOpen = true">
-                <template #leading><UiIcon name="plus" :size="13" /></template>
-                New hold
-              </UiButton>
-            </div>
-            <div class="empty">
-              <UiIcon name="shield" :size="28" stroke="var(--text-mute)" />
-              <div class="empty-title">No active holds</div>
-              <div class="empty-body">When legal review is needed, place a hold on specific users or date ranges to prevent deletion.</div>
-            </div>
-          </Card>
-        </div>
+        <Card class="managed">
+          <UiIcon name="shield" :size="28" stroke="var(--text-mute)" />
+          <div class="managed-title">{{ tab === 'forwarding' ? 'Forwarding rules' : tab === 'filters' ? 'Spam & content filtering' : 'Compliance & retention' }} are managed by Dezky</div>
+          <div class="managed-body">
+            <template v-if="tab === 'forwarding'">
+              Conditional forwarding runs on the shared mail platform. To route addresses today, use <strong>Aliases</strong> (one address → a mailbox) or <strong>Distribution lists</strong> (one address → many). Rule-based forwarding is on the roadmap.
+            </template>
+            <template v-else-if="tab === 'filters'">
+              Inbound mail passes through Dezky's reputation engine and Bayesian spam filter — tuned and updated centrally for every workspace. Per-workspace filter rules aren't configurable here.
+            </template>
+            <template v-else>
+              Mail retention and legal-hold policies are applied platform-wide for EU compliance. Contact Dezky to adjust retention for your organisation.
+            </template>
+          </div>
+        </Card>
       </template>
     </div>
 
-    <!-- Add alias modal (stub) -->
-    <Modal :open="addAliasOpen" eyebrow="Mail · aliases" title="Add alias" size="md" @close="addAliasOpen = false">
+    <!-- Add alias modal -->
+    <Modal :open="aliasOpen" eyebrow="Mail · aliases" title="Add alias" size="md" @close="aliasOpen = false">
       <div class="form-stack">
         <label class="field"><Eyebrow>Alias address</Eyebrow>
           <div class="alias-row">
-            <input class="input" value="marketing" placeholder="prefix" />
+            <input class="input" v-model="aliasForm.localPart" placeholder="sales" />
             <span class="at">@</span>
-            <select class="input"><option>dezky.com</option><option>baslund.dk</option></select>
+            <select class="input" v-model="aliasForm.domain">
+              <option v-for="d in domains" :key="d.id" :value="d.domain">{{ d.domain }}</option>
+            </select>
           </div>
         </label>
-        <label class="field"><Eyebrow>Route to user</Eyebrow><input class="input" value="frederik@dezky.com" /></label>
-      </div>
-      <template #footer>
-        <UiButton variant="ghost" @click="addAliasOpen = false">Cancel</UiButton>
-        <UiButton variant="primary" @click="addAliasOpen = false">
-          <template #leading><UiIcon name="check" :size="13" /></template>
-          Create alias
-        </UiButton>
-      </template>
-    </Modal>
-
-    <!-- Forwarding rule modal -->
-    <Modal :open="ruleOpen" eyebrow="Mail · forwarding" title="New forwarding rule" size="md" @close="ruleOpen = false">
-      <div class="form-stack">
-        <label class="field"><Eyebrow>Rule name</Eyebrow><input class="input" placeholder="Out-of-hours to on-call" /></label>
-        <label class="field"><Eyebrow>When</Eyebrow><input class="input" placeholder="subject: …" /></label>
-        <label class="field"><Eyebrow>Forward to</Eyebrow><input class="input" placeholder="oncall@dezky.com" /></label>
-      </div>
-      <template #footer>
-        <UiButton variant="ghost" @click="ruleOpen = false">Cancel</UiButton>
-        <UiButton variant="primary" @click="ruleOpen = false">
-          <template #leading><UiIcon name="check" :size="13" /></template>
-          Save rule
-        </UiButton>
-      </template>
-    </Modal>
-
-    <!-- New filter modal -->
-    <Modal :open="filterOpen" eyebrow="Mail · filters" title="New content filter" size="md" @close="filterOpen = false">
-      <div class="form-stack">
-        <label class="field"><Eyebrow>Filter name</Eyebrow><input class="input" placeholder="Block executable attachments" /></label>
-        <label class="field"><Eyebrow>Match expression</Eyebrow><input class="input" placeholder="attachment ext in (.exe, .scr, .bat)" /></label>
-        <label class="field"><Eyebrow>Action</Eyebrow>
-          <select class="input"><option>reject</option><option>quarantine</option><option>add tag</option></select>
+        <label class="field"><Eyebrow>Delivers to mailbox</Eyebrow>
+          <select class="input" v-model="aliasForm.destinationUserId">
+            <option v-for="u in mailboxUsers" :key="u._id" :value="u._id">{{ u.name }} · {{ u.email }}</option>
+          </select>
         </label>
       </div>
       <template #footer>
-        <UiButton variant="ghost" @click="filterOpen = false">Cancel</UiButton>
-        <UiButton variant="primary" @click="filterOpen = false">Create filter</UiButton>
+        <UiButton variant="ghost" @click="aliasOpen = false">Cancel</UiButton>
+        <UiButton variant="primary" :disabled="aliasBusy || !aliasForm.localPart.trim() || !aliasForm.destinationUserId" @click="submitAlias">
+          {{ aliasBusy ? 'Creating…' : 'Create alias' }}
+        </UiButton>
       </template>
     </Modal>
 
+    <ConfirmDialog
+      :open="!!aliasDeleteTarget"
+      eyebrow="Mail · aliases"
+      :title="`Delete ${aliasDeleteTarget?.address}?`"
+      confirm-label="Delete alias"
+      tone="danger"
+      :busy="aliasDeleting"
+      @close="aliasDeleteTarget = null"
+      @confirm="confirmDeleteAlias"
+    >
+      Mail to <strong>{{ aliasDeleteTarget?.address }}</strong> will stop being delivered. The destination mailbox is unaffected.
+    </ConfirmDialog>
+
     <!-- New list modal -->
     <Modal :open="listOpen" eyebrow="Mail · lists" title="New distribution list" size="md" @close="listOpen = false">
       <div class="form-stack">
-        <label class="field"><Eyebrow>List name</Eyebrow><input class="input" placeholder="Engineering" /></label>
-        <label class="field"><Eyebrow>Alias</Eyebrow><input class="input" placeholder="eng@dezky.com" /></label>
-        <label class="field"><Eyebrow>Owner</Eyebrow><input class="input" value="Anne Baslund" /></label>
+        <label class="field"><Eyebrow>List address</Eyebrow>
+          <div class="alias-row">
+            <input class="input" v-model="listForm.localPart" placeholder="team" />
+            <span class="at">@</span>
+            <select class="input" v-model="listForm.domain">
+              <option v-for="d in domains" :key="d.id" :value="d.domain">{{ d.domain }}</option>
+            </select>
+          </div>
+        </label>
+        <label class="field"><Eyebrow>Description <span class="opt">optional</span></Eyebrow><input class="input" v-model="listForm.description" placeholder="Everyone in engineering" /></label>
+        <label class="field"><Eyebrow>Members <span class="opt">one email per line</span></Eyebrow>
+          <textarea class="input area" v-model="listForm.recipientsText" rows="4" placeholder="anne@acme.dk&#10;mikkel@acme.dk"></textarea>
+        </label>
       </div>
       <template #footer>
         <UiButton variant="ghost" @click="listOpen = false">Cancel</UiButton>
-        <UiButton variant="primary" @click="listOpen = false">Create list</UiButton>
+        <UiButton variant="primary" :disabled="listBusy || !listForm.localPart.trim()" @click="submitList">
+          {{ listBusy ? 'Creating…' : 'Create list' }}
+        </UiButton>
       </template>
     </Modal>
 
-    <!-- Manage list side panel -->
-    <SidePanel :open="!!openList" eyebrow="Distribution list" :title="openList?.name || ''" width="lg" @close="openList = null">
+    <!-- Manage list members -->
+    <SidePanel :open="!!openList" eyebrow="Distribution list" :title="openList?.address || ''" width="lg" @close="openList = null">
       <div v-if="openList" class="manage">
-        <div class="manage-head">
-          <div class="manage-icon"><UiIcon name="users" :size="20" /></div>
-          <div class="manage-meta">
-            <div class="manage-name">{{ openList.name }}</div>
-            <Mono dim>{{ openList.alias }}</Mono>
-          </div>
-          <Badge :tone="openList.moderation === 'open' ? 'ok' : 'neutral'">{{ openList.moderation }}</Badge>
-        </div>
-        <div class="manage-stats">
-          <div><Eyebrow>Members</Eyebrow><div class="ms-v">{{ openList.members }}</div></div>
-          <div><Eyebrow>Owner</Eyebrow><div class="ms-v">{{ openList.owner }}</div></div>
-          <div><Eyebrow>Posts this week</Eyebrow><div class="ms-v">{{ openList.members > 8 ? '142' : openList.members > 2 ? '38' : '6' }}</div></div>
-        </div>
+        <Eyebrow>Members <span class="opt">one email per line</span></Eyebrow>
+        <textarea class="input area" v-model="manageText" rows="12" />
       </div>
       <template #footer>
-        <UiButton variant="danger" @click="deleteListOpen = true">
+        <UiButton variant="danger" @click="openList && (listDeleteTarget = openList)">
           <template #leading><UiIcon name="trash" :size="13" /></template>
           Delete list
         </UiButton>
         <div style="flex: 1" />
-        <UiButton variant="secondary" @click="openList = null">Discard</UiButton>
-        <UiButton variant="primary" @click="openList = null; toast.ok('List saved')">
-          <template #leading><UiIcon name="check" :size="13" /></template>
-          Save changes
-        </UiButton>
+        <UiButton variant="secondary" @click="openList = null">Cancel</UiButton>
+        <UiButton variant="primary" :disabled="manageBusy" @click="saveList">{{ manageBusy ? 'Saving…' : 'Save members' }}</UiButton>
       </template>
     </SidePanel>
 
-    <!-- Confirm delete list -->
     <ConfirmDialog
-      :open="deleteListOpen"
+      :open="!!listDeleteTarget"
       eyebrow="Distribution list"
-      :title="`Delete ${openList?.name || ''}?`"
+      :title="`Delete ${listDeleteTarget?.address}?`"
       confirm-label="Delete list"
       tone="danger"
-      @close="deleteListOpen = false"
+      :busy="listDeleting"
+      @close="listDeleteTarget = null"
       @confirm="confirmDeleteList"
     >
-      Mail sent to this list will start bouncing immediately. Existing replies in members' inboxes are unaffected.
+      Mail to this list will start bouncing immediately. Members' existing inboxes are unaffected.
     </ConfirmDialog>
-
-    <!-- Legal hold modal -->
-    <Modal :open="holdOpen" eyebrow="Compliance · legal hold" title="Place legal hold" size="md" @close="holdOpen = false">
-      <div class="form-stack">
-        <label class="field"><Eyebrow>Case name</Eyebrow><input class="input" placeholder="Case 2026-Q3-DPA-001" /></label>
-        <label class="field"><Eyebrow>Scope · users</Eyebrow><input class="input" placeholder="anne@, mikkel@, frederik@" /></label>
-        <label class="field"><Eyebrow>Date range</Eyebrow><input class="input" placeholder="2026-01-01 → 2026-12-31" /></label>
-      </div>
-      <template #footer>
-        <UiButton variant="ghost" @click="holdOpen = false">Cancel</UiButton>
-        <UiButton variant="primary" @click="holdOpen = false">Place hold</UiButton>
-      </template>
-    </Modal>
   </div>
 </template>
 
@@ -439,121 +391,36 @@ function toneFor(action: string): 'bad' | 'warn' | 'info' {
 .tab-wrap { padding: 16px 40px 0 40px; }
 .content { padding: 20px 40px 64px 40px; }
 
-.row { display: flex; align-items: center; justify-content: space-between; margin-bottom: 12px; }
+.row { display: flex; align-items: center; justify-content: space-between; margin-bottom: 12px; gap: 16px; }
 .lead { font-size: 13px; color: var(--text-mute); max-width: 540px; line-height: 1.5; }
 
+.notice { display: flex; align-items: center; gap: 10px; font-size: 13px; color: var(--text-mute); }
+
 .tbl { width: 100%; border-collapse: collapse; }
-.tbl th {
-  text-align: left;
-  font-family: var(--font-mono);
-  font-size: 10px;
-  letter-spacing: 0.12em;
-  text-transform: uppercase;
-  color: var(--text-mute);
-  padding: 12px 16px;
-  border-bottom: 1px solid var(--border);
-  font-weight: 500;
-}
+.tbl th { text-align: left; font-family: var(--font-mono); font-size: 10px; letter-spacing: 0.12em; text-transform: uppercase; color: var(--text-mute); padding: 12px 16px; border-bottom: 1px solid var(--border); font-weight: 500; }
 .tbl td { padding: 12px 16px; border-bottom: 1px solid var(--border); font-size: 13px; }
 .tbl tr:last-child td { border-bottom: none; }
-.tbl .right { text-align: right; }
-
-.rules { display: flex; flex-direction: column; gap: 10px; }
-.rule-row { display: flex; align-items: center; gap: 14px; }
-.rule-meta { flex: 1; }
-.rule-name { font-size: 14px; font-weight: 500; }
-.rule-line { display: flex; align-items: center; gap: 8px; margin-top: 6px; font-size: 12px; }
-.rule-match { font-family: var(--font-mono); color: var(--text-dim); }
-
-.toggle {
-  width: 32px;
-  height: 18px;
-  border-radius: 999px;
-  background: var(--border);
-  border: none;
-  position: relative;
-  cursor: pointer;
-  padding: 0;
-  flex-shrink: 0;
-}
-.toggle span {
-  position: absolute;
-  top: 2px;
-  left: 2px;
-  width: 14px;
-  height: 14px;
-  border-radius: 999px;
-  background: var(--bg);
-  transition: left 120ms;
-}
-.toggle.on { background: var(--text); }
-.toggle.on span { left: 16px; background: var(--accent); }
-
-.filter-name { display: flex; align-items: center; gap: 10px; }
-.builtin {
-  margin-top: 16px;
-  padding: 14px;
-  background: var(--bg);
-  border-radius: 6px;
-  border: 1px solid var(--border);
-  display: flex;
-  align-items: flex-start;
-  gap: 12px;
-}
-.builtin-title { font-size: 13px; font-weight: 600; }
-.builtin-sub { color: var(--text-mute); margin-top: 4px; font-size: 13px; }
+.tbl .right { text-align: right; white-space: nowrap; }
 
 .lists { display: grid; grid-template-columns: repeat(2, 1fr); gap: 12px; }
 .list-head { display: flex; align-items: flex-start; justify-content: space-between; gap: 12px; }
 .list-title { display: flex; align-items: center; gap: 8px; }
 .list-name { font-family: var(--font-display); font-weight: 600; font-size: 16px; }
-.list-row { display: flex; gap: 18px; margin-top: 18px; padding-top: 14px; border-top: 1px solid var(--border); align-items: flex-end; }
-.list-num { font-family: var(--font-display); font-weight: 600; font-size: 20px; margin-top: 4px; }
-.list-owner { flex: 1; font-size: 13px; }
+.list-desc { font-size: 12px; color: var(--text-mute); margin-top: 10px; }
+.list-row { display: flex; gap: 8px; margin-top: 16px; padding-top: 14px; border-top: 1px solid var(--border); }
 
-.compliance { display: flex; flex-direction: column; gap: 16px; max-width: 900px; }
-.card-head { margin-bottom: 12px; }
-.card-head-inline { display: flex; align-items: flex-start; justify-content: space-between; gap: 12px; }
-.card-title { font-family: var(--font-display); font-weight: 600; font-size: 18px; letter-spacing: -0.01em; margin-top: 4px; }
-.card-sub { font-size: 13px; color: var(--text-mute); margin-top: 4px; }
-.muted { font-size: 13px; color: var(--text-mute); line-height: 1.6; }
-.radio-big { display: flex; flex-direction: column; gap: 8px; }
-.radio-big label { display: flex; gap: 12px; padding: 14px; border: 1px solid var(--border); border-radius: 6px; cursor: pointer; }
-.radio-big label.active { border-color: var(--text); background: var(--bg); }
-.radio-big input { display: none; }
-.radio-dot { width: 18px; height: 18px; border-radius: 999px; border: 2px solid var(--border); display: inline-flex; align-items: center; justify-content: center; flex-shrink: 0; margin-top: 2px; }
-.radio-big label.active .radio-dot { border-color: var(--text); }
-.radio-dot span { width: 8px; height: 8px; border-radius: 999px; background: var(--text); }
-.radio-label { font-size: 14px; font-weight: 500; }
-.radio-d { font-size: 12px; color: var(--text-mute); margin-top: 4px; }
+.managed { display: flex; flex-direction: column; align-items: center; text-align: center; gap: 10px; padding: 48px 32px; max-width: 640px; margin: 0 auto; }
+.managed-title { font-family: var(--font-display); font-weight: 600; font-size: 17px; }
+.managed-body { font-size: 13px; color: var(--text-mute); line-height: 1.6; max-width: 480px; }
 
-.empty { padding: 36px 24px; text-align: center; display: flex; flex-direction: column; align-items: center; gap: 8px; }
-.empty-title { font-family: var(--font-display); font-weight: 600; font-size: 15px; }
-.empty-body { font-size: 13px; color: var(--text-mute); max-width: 420px; line-height: 1.5; }
-
-/* Modal forms */
 .form-stack { display: flex; flex-direction: column; gap: 14px; }
 .field { display: flex; flex-direction: column; gap: 6px; }
+.opt { font-weight: 400; color: var(--text-mute); text-transform: none; letter-spacing: 0; }
 .input { height: 36px; padding: 0 12px; background: var(--surface); border: 1px solid var(--border); border-radius: 6px; font-family: inherit; font-size: 13px; color: var(--text); outline: none; }
 .input:focus { border-color: var(--text); }
+.area { height: auto; padding: 10px 12px; font-family: var(--font-mono); line-height: 1.5; resize: vertical; }
 .alias-row { display: grid; grid-template-columns: 1fr auto 1fr; gap: 8px; align-items: center; }
 .at { font-family: var(--font-mono); color: var(--text-mute); }
 
-.manage { padding-bottom: 24px; }
-.manage-head { display: flex; align-items: center; gap: 14px; }
-.manage-icon {
-  width: 44px;
-  height: 44px;
-  border-radius: 10px;
-  background: var(--bg);
-  border: 1px solid var(--border);
-  display: inline-flex;
-  align-items: center;
-  justify-content: center;
-  color: var(--text-dim);
-}
-.manage-meta { flex: 1; min-width: 0; }
-.manage-name { font-family: var(--font-display); font-weight: 600; font-size: 18px; }
-.manage-stats { display: flex; gap: 24px; margin-top: 16px; }
-.ms-v { font-size: 13px; margin-top: 4px; font-weight: 500; }
+.manage { padding-bottom: 16px; display: flex; flex-direction: column; gap: 8px; }
 </style>
diff --git a/apps/portal/server/api/tenants/[slug]/mail/aliases.get.ts b/apps/portal/server/api/tenants/[slug]/mail/aliases.get.ts
new file mode 100644
index 0000000..f87472f
--- /dev/null
+++ b/apps/portal/server/api/tenants/[slug]/mail/aliases.get.ts
@@ -0,0 +1,13 @@
+// List the tenant's email aliases. Proxies GET /tenants/:slug/mail/aliases.
+import { getUserSession } from 'nuxt-oidc-auth/runtime/server/utils/session.js'
+
+export default defineEventHandler(async (event) => {
+  const session = await getUserSession(event).catch(() => null)
+  const accessToken = (session as { accessToken?: string } | null)?.accessToken
+  if (!accessToken) throw createError({ statusCode: 401, statusMessage: 'Not signed in' })
+  const slug = getRouterParam(event, 'slug')
+  const base = process.env.PLATFORM_API_INTERNAL_URL ?? 'http://platform-api:3001'
+  return $fetch(`${base}/tenants/${slug}/mail/aliases`, {
+    headers: { Authorization: `Bearer ${accessToken}` },
+  })
+})
diff --git a/apps/portal/server/api/tenants/[slug]/mail/aliases.post.ts b/apps/portal/server/api/tenants/[slug]/mail/aliases.post.ts
new file mode 100644
index 0000000..a2a2ce7
--- /dev/null
+++ b/apps/portal/server/api/tenants/[slug]/mail/aliases.post.ts
@@ -0,0 +1,16 @@
+// Create an email alias. Proxies POST /tenants/:slug/mail/aliases.
+import { getUserSession } from 'nuxt-oidc-auth/runtime/server/utils/session.js'
+
+export default defineEventHandler(async (event) => {
+  const session = await getUserSession(event).catch(() => null)
+  const accessToken = (session as { accessToken?: string } | null)?.accessToken
+  if (!accessToken) throw createError({ statusCode: 401, statusMessage: 'Not signed in' })
+  const slug = getRouterParam(event, 'slug')
+  const body = await readBody(event)
+  const base = process.env.PLATFORM_API_INTERNAL_URL ?? 'http://platform-api:3001'
+  return $fetch(`${base}/tenants/${slug}/mail/aliases`, {
+    method: 'POST',
+    headers: { Authorization: `Bearer ${accessToken}` },
+    body,
+  })
+})
diff --git a/apps/portal/server/api/tenants/[slug]/mail/aliases/[address].delete.ts b/apps/portal/server/api/tenants/[slug]/mail/aliases/[address].delete.ts
new file mode 100644
index 0000000..86fea4c
--- /dev/null
+++ b/apps/portal/server/api/tenants/[slug]/mail/aliases/[address].delete.ts
@@ -0,0 +1,16 @@
+// Delete an email alias. Proxies DELETE /tenants/:slug/mail/aliases/:address.
+import { getUserSession } from 'nuxt-oidc-auth/runtime/server/utils/session.js'
+
+export default defineEventHandler(async (event) => {
+  const session = await getUserSession(event).catch(() => null)
+  const accessToken = (session as { accessToken?: string } | null)?.accessToken
+  if (!accessToken) throw createError({ statusCode: 401, statusMessage: 'Not signed in' })
+  const slug = getRouterParam(event, 'slug')
+  const address = getRouterParam(event, 'address')
+  const base = process.env.PLATFORM_API_INTERNAL_URL ?? 'http://platform-api:3001'
+  await $fetch(`${base}/tenants/${slug}/mail/aliases/${encodeURIComponent(address ?? '')}`, {
+    method: 'DELETE',
+    headers: { Authorization: `Bearer ${accessToken}` },
+  })
+  return { ok: true }
+})
diff --git a/apps/portal/server/api/tenants/[slug]/mail/lists.get.ts b/apps/portal/server/api/tenants/[slug]/mail/lists.get.ts
new file mode 100644
index 0000000..4d90522
--- /dev/null
+++ b/apps/portal/server/api/tenants/[slug]/mail/lists.get.ts
@@ -0,0 +1,13 @@
+// List the tenant's distribution lists. Proxies GET /tenants/:slug/mail/lists.
+import { getUserSession } from 'nuxt-oidc-auth/runtime/server/utils/session.js'
+
+export default defineEventHandler(async (event) => {
+  const session = await getUserSession(event).catch(() => null)
+  const accessToken = (session as { accessToken?: string } | null)?.accessToken
+  if (!accessToken) throw createError({ statusCode: 401, statusMessage: 'Not signed in' })
+  const slug = getRouterParam(event, 'slug')
+  const base = process.env.PLATFORM_API_INTERNAL_URL ?? 'http://platform-api:3001'
+  return $fetch(`${base}/tenants/${slug}/mail/lists`, {
+    headers: { Authorization: `Bearer ${accessToken}` },
+  })
+})
diff --git a/apps/portal/server/api/tenants/[slug]/mail/lists.post.ts b/apps/portal/server/api/tenants/[slug]/mail/lists.post.ts
new file mode 100644
index 0000000..fc1cff8
--- /dev/null
+++ b/apps/portal/server/api/tenants/[slug]/mail/lists.post.ts
@@ -0,0 +1,16 @@
+// Create a distribution list. Proxies POST /tenants/:slug/mail/lists.
+import { getUserSession } from 'nuxt-oidc-auth/runtime/server/utils/session.js'
+
+export default defineEventHandler(async (event) => {
+  const session = await getUserSession(event).catch(() => null)
+  const accessToken = (session as { accessToken?: string } | null)?.accessToken
+  if (!accessToken) throw createError({ statusCode: 401, statusMessage: 'Not signed in' })
+  const slug = getRouterParam(event, 'slug')
+  const body = await readBody(event)
+  const base = process.env.PLATFORM_API_INTERNAL_URL ?? 'http://platform-api:3001'
+  return $fetch(`${base}/tenants/${slug}/mail/lists`, {
+    method: 'POST',
+    headers: { Authorization: `Bearer ${accessToken}` },
+    body,
+  })
+})
diff --git a/apps/portal/server/api/tenants/[slug]/mail/lists/[id].delete.ts b/apps/portal/server/api/tenants/[slug]/mail/lists/[id].delete.ts
new file mode 100644
index 0000000..cb36603
--- /dev/null
+++ b/apps/portal/server/api/tenants/[slug]/mail/lists/[id].delete.ts
@@ -0,0 +1,16 @@
+// Delete a distribution list. Proxies DELETE /tenants/:slug/mail/lists/:id.
+import { getUserSession } from 'nuxt-oidc-auth/runtime/server/utils/session.js'
+
+export default defineEventHandler(async (event) => {
+  const session = await getUserSession(event).catch(() => null)
+  const accessToken = (session as { accessToken?: string } | null)?.accessToken
+  if (!accessToken) throw createError({ statusCode: 401, statusMessage: 'Not signed in' })
+  const slug = getRouterParam(event, 'slug')
+  const id = getRouterParam(event, 'id')
+  const base = process.env.PLATFORM_API_INTERNAL_URL ?? 'http://platform-api:3001'
+  await $fetch(`${base}/tenants/${slug}/mail/lists/${id}`, {
+    method: 'DELETE',
+    headers: { Authorization: `Bearer ${accessToken}` },
+  })
+  return { ok: true }
+})
diff --git a/apps/portal/server/api/tenants/[slug]/mail/lists/[id].patch.ts b/apps/portal/server/api/tenants/[slug]/mail/lists/[id].patch.ts
new file mode 100644
index 0000000..abba0a3
--- /dev/null
+++ b/apps/portal/server/api/tenants/[slug]/mail/lists/[id].patch.ts
@@ -0,0 +1,17 @@
+// Update a distribution list's recipients. Proxies PATCH /tenants/:slug/mail/lists/:id.
+import { getUserSession } from 'nuxt-oidc-auth/runtime/server/utils/session.js'
+
+export default defineEventHandler(async (event) => {
+  const session = await getUserSession(event).catch(() => null)
+  const accessToken = (session as { accessToken?: string } | null)?.accessToken
+  if (!accessToken) throw createError({ statusCode: 401, statusMessage: 'Not signed in' })
+  const slug = getRouterParam(event, 'slug')
+  const id = getRouterParam(event, 'id')
+  const body = await readBody(event)
+  const base = process.env.PLATFORM_API_INTERNAL_URL ?? 'http://platform-api:3001'
+  return $fetch(`${base}/tenants/${slug}/mail/lists/${id}`, {
+    method: 'PATCH',
+    headers: { Authorization: `Bearer ${accessToken}` },
+    body,
+  })
+})
diff --git a/apps/portal/types/workspace.ts b/apps/portal/types/workspace.ts
index 11a1522..0ffb219 100644
--- a/apps/portal/types/workspace.ts
+++ b/apps/portal/types/workspace.ts
@@ -100,6 +100,9 @@ export interface TenantUserDoc {
   active: boolean
   lastLoginAt?: string
   createdAt?: string
+  // Present when the user has a provisioned Stalwart mailbox (i.e. can receive
+  // mail / be an alias destination). Absent for SSO-only users.
+  mailboxAddress?: string
 }
 
 // The card on file, as returned by GET /tenants/:slug/payment-method (null when
diff --git a/services/platform-api/src/app.module.ts b/services/platform-api/src/app.module.ts
index b134b8a..48067e1 100644
--- a/services/platform-api/src/app.module.ts
+++ b/services/platform-api/src/app.module.ts
@@ -8,6 +8,7 @@ import { DomainsModule } from './domains/domains.module.js'
 import { FlagsModule } from './flags/flags.module.js'
 import { HealthModule } from './health/health.module.js'
 import { IngestModule } from './ingest/ingest.module.js'
+import { MailModule } from './mail/mail.module.js'
 import { MeModule } from './me/me.module.js'
 import { PartnersModule } from './partners/partners.module.js'
 import { PricesModule } from './prices/prices.module.js'
@@ -27,6 +28,7 @@ import { UsersModule } from './users/users.module.js'
     HealthModule,
     TenantsModule,
     DomainsModule,
+    MailModule,
     PartnersModule,
     UsersModule,
     MeModule,
diff --git a/services/platform-api/src/integrations/stalwart.client.ts b/services/platform-api/src/integrations/stalwart.client.ts
index e0a7237..3a6333f 100644
--- a/services/platform-api/src/integrations/stalwart.client.ts
+++ b/services/platform-api/src/integrations/stalwart.client.ts
@@ -268,6 +268,154 @@ export class StalwartClient {
       throw new Error(`Stalwart mailbox delete failed (id=${accountId}): ${JSON.stringify(notDestroyed)}`)
     }
   }
+
+  // ── Aliases (extra addresses that route to a mailbox) ──────────────────────
+
+  // Every mailbox + its aliases. Stalwart's account query has no domain filter,
+  // so the caller narrows by domainId. `aliases` is an index-keyed map on the
+  // wire; we hand back a plain array.
+  async listAccountsWithAliases(): Promise<StalwartAccountAliases[]> {
+    const resp = await this.jmap([
+      ['x:Account/query', { filter: {} }, '0'],
+      [
+        'x:Account/get',
+        {
+          '#ids': { resultOf: '0', name: 'x:Account/query', path: '/ids' },
+          properties: ['emailAddress', 'aliases'],
+        },
+        '1',
+      ],
+    ])
+    const list = (resp[1]?.[1]?.list ?? []) as Array<{
+      id: string
+      emailAddress: string
+      aliases?: Record<string, StalwartAlias>
+    }>
+    return list.map((a) => ({
+      id: a.id,
+      emailAddress: a.emailAddress,
+      aliases: aliasMapToArray(a.aliases),
+    }))
+  }
+
+  // Add an alias (localpart@domain) that delivers to this mailbox. Idempotent.
+  async addAlias(accountId: string, name: string, domainId: string): Promise<void> {
+    const aliases = await this.getAccountAliases(accountId)
+    if (aliases.some((a) => a.name === name && a.domainId === domainId)) return
+    aliases.push({ name, domainId, enabled: true })
+    await this.writeAliases(accountId, aliases)
+  }
+
+  async removeAlias(accountId: string, name: string, domainId: string): Promise<void> {
+    const aliases = (await this.getAccountAliases(accountId)).filter(
+      (a) => !(a.name === name && a.domainId === domainId),
+    )
+    await this.writeAliases(accountId, aliases)
+  }
+
+  private async getAccountAliases(accountId: string): Promise<StalwartAlias[]> {
+    const resp = await this.jmap([
+      ['x:Account/get', { ids: [accountId], properties: ['aliases'] }, '0'],
+    ])
+    return aliasMapToArray(resp[0]?.[1]?.list?.[0]?.aliases)
+  }
+
+  // Stalwart replaces the whole `aliases` field on update, so we always write the
+  // full set back as an index-keyed map.
+  private async writeAliases(accountId: string, aliases: StalwartAlias[]): Promise<void> {
+    const map: Record<string, StalwartAlias> = {}
+    aliases.forEach((a, i) => {
+      map[String(i)] = { name: a.name, domainId: a.domainId, enabled: a.enabled }
+    })
+    const resp = await this.jmap([
+      ['x:Account/set', { update: { [accountId]: { aliases: map } } }, '0'],
+    ])
+    const notUpdated = resp[0][1].notUpdated?.[accountId]
+    if (notUpdated) {
+      throw new Error(`Stalwart alias update failed (id=${accountId}): ${JSON.stringify(notUpdated)}`)
+    }
+  }
+
+  // ── Mailing lists (one address fans out to many recipients) ────────────────
+
+  async listMailingLists(): Promise<StalwartMailingList[]> {
+    const resp = await this.jmap([
+      ['x:MailingList/query', { filter: {} }, '0'],
+      [
+        'x:MailingList/get',
+        {
+          '#ids': { resultOf: '0', name: 'x:MailingList/query', path: '/ids' },
+          properties: ['name', 'emailAddress', 'domainId', 'recipients', 'description'],
+        },
+        '1',
+      ],
+    ])
+    const list = (resp[1]?.[1]?.list ?? []) as Array<{
+      id: string
+      name: string
+      emailAddress: string
+      domainId: string
+      recipients?: Record<string, boolean>
+      description?: string
+    }>
+    return list.map((l) => ({
+      id: l.id,
+      name: l.name,
+      emailAddress: l.emailAddress,
+      domainId: l.domainId,
+      recipients: l.recipients ? Object.keys(l.recipients) : [],
+      description: l.description,
+    }))
+  }
+
+  async createMailingList(input: {
+    domainId: string
+    name: string
+    recipients: string[]
+    description?: string
+  }): Promise<{ id: string }> {
+    const resp = await this.jmap([
+      [
+        'x:MailingList/set',
+        {
+          create: {
+            l1: {
+              name: input.name,
+              domainId: input.domainId,
+              description: input.description ?? null,
+              recipients: recipientsToMap(input.recipients),
+            },
+          },
+        },
+        '0',
+      ],
+    ])
+    const created = resp[0][1].created?.l1
+    if (!created?.id) {
+      throw new Error(`Stalwart mailing list create failed: ${JSON.stringify(resp[0][1].notCreated)}`)
+    }
+    return { id: created.id }
+  }
+
+  async updateMailingListRecipients(id: string, recipients: string[]): Promise<void> {
+    const resp = await this.jmap([
+      ['x:MailingList/set', { update: { [id]: { recipients: recipientsToMap(recipients) } } }, '0'],
+    ])
+    const notUpdated = resp[0][1].notUpdated?.[id]
+    if (notUpdated) {
+      throw new Error(`Stalwart mailing list update failed (id=${id}): ${JSON.stringify(notUpdated)}`)
+    }
+  }
+
+  async deleteMailingList(id: string): Promise<void> {
+    const resp = await this.jmap([['x:MailingList/set', { destroy: [id] }, '0']])
+    const result = resp[0][1]
+    if ((result.destroyed as string[] | undefined)?.includes(id)) return
+    const notDestroyed = result.notDestroyed?.[id]
+    if (notDestroyed && notDestroyed.type !== 'notFound') {
+      throw new Error(`Stalwart mailing list delete failed (id=${id}): ${JSON.stringify(notDestroyed)}`)
+    }
+  }
 }
 
 export interface StalwartLinkedObject {
@@ -275,6 +423,42 @@ export interface StalwartLinkedObject {
   id: string
 }
 
+export interface StalwartAlias {
+  name: string
+  domainId: string
+  enabled: boolean
+}
+
+export interface StalwartAccountAliases {
+  id: string
+  emailAddress: string
+  aliases: StalwartAlias[]
+}
+
+export interface StalwartMailingList {
+  id: string
+  name: string
+  emailAddress: string
+  domainId: string
+  recipients: string[]
+  description?: string
+}
+
+function aliasMapToArray(map?: Record<string, StalwartAlias>): StalwartAlias[] {
+  if (!map) return []
+  return Object.values(map).map((a) => ({
+    name: a.name,
+    domainId: a.domainId,
+    enabled: a.enabled !== false,
+  }))
+}
+
+function recipientsToMap(recipients: string[]): Record<string, boolean> {
+  const map: Record<string, boolean> = {}
+  for (const r of recipients) map[r.trim().toLowerCase()] = true
+  return map
+}
+
 // Thrown when a domain still has accounts, aliases or mailing lists in Stalwart
 // and therefore can't be removed. `linkedObjects` excludes the auto-generated
 // DKIM signatures (which we remove automatically).
diff --git a/services/platform-api/src/mail/dto/create-alias.dto.ts b/services/platform-api/src/mail/dto/create-alias.dto.ts
new file mode 100644
index 0000000..c9a30ab
--- /dev/null
+++ b/services/platform-api/src/mail/dto/create-alias.dto.ts
@@ -0,0 +1,17 @@
+import { IsMongoId, IsString, Matches, MaxLength } from 'class-validator'
+
+// Create an email alias `localPart@domain` that delivers to an existing mailbox
+// user (the destination). Both must belong to the tenant.
+export class CreateAliasDto {
+  @IsString()
+  @MaxLength(64)
+  @Matches(/^[a-zA-Z0-9._-]+$/, { message: 'alias prefix may only contain letters, numbers, dots, hyphens and underscores' })
+  localPart!: string
+
+  @IsString()
+  domain!: string
+
+  // The destination mailbox user (our User _id); the alias is added to their account.
+  @IsMongoId()
+  destinationUserId!: string
+}
diff --git a/services/platform-api/src/mail/dto/create-list.dto.ts b/services/platform-api/src/mail/dto/create-list.dto.ts
new file mode 100644
index 0000000..fbd7367
--- /dev/null
+++ b/services/platform-api/src/mail/dto/create-list.dto.ts
@@ -0,0 +1,23 @@
+import { ArrayMaxSize, IsArray, IsEmail, IsOptional, IsString, Matches, MaxLength } from 'class-validator'
+
+// Create a distribution list `localPart@domain` that fans mail out to recipients.
+export class CreateListDto {
+  @IsString()
+  @MaxLength(64)
+  @Matches(/^[a-zA-Z0-9._-]+$/, { message: 'list prefix may only contain letters, numbers, dots, hyphens and underscores' })
+  localPart!: string
+
+  @IsString()
+  domain!: string
+
+  @IsOptional()
+  @IsString()
+  @MaxLength(200)
+  description?: string
+
+  @IsOptional()
+  @IsArray()
+  @ArrayMaxSize(1000)
+  @IsEmail({}, { each: true })
+  recipients?: string[]
+}
diff --git a/services/platform-api/src/mail/dto/update-list.dto.ts b/services/platform-api/src/mail/dto/update-list.dto.ts
new file mode 100644
index 0000000..2a324da
--- /dev/null
+++ b/services/platform-api/src/mail/dto/update-list.dto.ts
@@ -0,0 +1,9 @@
+import { ArrayMaxSize, IsArray, IsEmail } from 'class-validator'
+
+// Replace a distribution list's recipients.
+export class UpdateListDto {
+  @IsArray()
+  @ArrayMaxSize(1000)
+  @IsEmail({}, { each: true })
+  recipients!: string[]
+}
diff --git a/services/platform-api/src/mail/mail.controller.ts b/services/platform-api/src/mail/mail.controller.ts
new file mode 100644
index 0000000..2e5e00c
--- /dev/null
+++ b/services/platform-api/src/mail/mail.controller.ts
@@ -0,0 +1,125 @@
+import {
+  Body,
+  Controller,
+  Delete,
+  ForbiddenException,
+  Get,
+  HttpCode,
+  Param,
+  Patch,
+  Post,
+  Req,
+  UseGuards,
+} from '@nestjs/common'
+import { ActorService } from '../auth/actor.service.js'
+import { clientIp } from '../auth/client-ip.js'
+import { CurrentUser } from '../auth/current-user.decorator.js'
+import { JwtAuthGuard } from '../auth/jwt-auth.guard.js'
+import type { AuthentikJwtPayload } from '../auth/jwt-payload.interface.js'
+import type { AuditActor } from '../audit/audit.service.js'
+import { TenantsService } from '../tenants/tenants.service.js'
+import { CreateAliasDto } from './dto/create-alias.dto.js'
+import { CreateListDto } from './dto/create-list.dto.js'
+import { UpdateListDto } from './dto/update-list.dto.js'
+import { MailService, type TenantRef } from './mail.service.js'
+
+function auditActor(
+  user: { _id: unknown; email: string },
+  req: Parameters<typeof clientIp>[0],
+): AuditActor {
+  return { userId: String(user._id), email: user.email, ip: clientIp(req) }
+}
+
+// Customer-admin Mail settings: aliases + distribution lists (the per-tenant
+// parts of Stalwart mail config). Forwarding / spam filters / retention are
+// server-global and stay operator-managed, so they aren't exposed here.
+@Controller('tenants/:slug/mail')
+@UseGuards(JwtAuthGuard)
+export class MailController {
+  constructor(
+    private readonly mail: MailService,
+    private readonly tenants: TenantsService,
+    private readonly actor: ActorService,
+  ) {}
+
+  private async gate(slug: string, jwt: AuthentikJwtPayload): Promise<{ actor: any; tenant: TenantRef }> {
+    const actor = await this.actor.resolve(jwt)
+    const tenant = await this.tenants.findOneBySlug(slug)
+    if (!actor.platformAdmin && !actor.tenantIds.some((id) => id.equals(tenant._id))) {
+      throw new ForbiddenException(`No access to tenant "${slug}"`)
+    }
+    return { actor, tenant: { _id: tenant._id, slug: tenant.slug } }
+  }
+
+  // ── Aliases ──
+  @Get('aliases')
+  async listAliases(@Param('slug') slug: string, @CurrentUser() jwt: AuthentikJwtPayload) {
+    const { tenant } = await this.gate(slug, jwt)
+    return this.mail.listAliases(tenant)
+  }
+
+  @Post('aliases')
+  async createAlias(
+    @Param('slug') slug: string,
+    @Body() dto: CreateAliasDto,
+    @CurrentUser() jwt: AuthentikJwtPayload,
+    @Req() req: Parameters<typeof clientIp>[0],
+  ) {
+    const { actor, tenant } = await this.gate(slug, jwt)
+    return this.mail.createAlias(tenant, dto, auditActor(actor, req))
+  }
+
+  @Delete('aliases/:address')
+  @HttpCode(204)
+  async deleteAlias(
+    @Param('slug') slug: string,
+    @Param('address') address: string,
+    @CurrentUser() jwt: AuthentikJwtPayload,
+    @Req() req: Parameters<typeof clientIp>[0],
+  ) {
+    const { actor, tenant } = await this.gate(slug, jwt)
+    await this.mail.deleteAlias(tenant, address, auditActor(actor, req))
+  }
+
+  // ── Distribution lists ──
+  @Get('lists')
+  async listLists(@Param('slug') slug: string, @CurrentUser() jwt: AuthentikJwtPayload) {
+    const { tenant } = await this.gate(slug, jwt)
+    return this.mail.listLists(tenant)
+  }
+
+  @Post('lists')
+  async createList(
+    @Param('slug') slug: string,
+    @Body() dto: CreateListDto,
+    @CurrentUser() jwt: AuthentikJwtPayload,
+    @Req() req: Parameters<typeof clientIp>[0],
+  ) {
+    const { actor, tenant } = await this.gate(slug, jwt)
+    return this.mail.createList(tenant, dto, auditActor(actor, req))
+  }
+
+  @Patch('lists/:id')
+  async updateList(
+    @Param('slug') slug: string,
+    @Param('id') id: string,
+    @Body() dto: UpdateListDto,
+    @CurrentUser() jwt: AuthentikJwtPayload,
+    @Req() req: Parameters<typeof clientIp>[0],
+  ) {
+    const { actor, tenant } = await this.gate(slug, jwt)
+    return this.mail.updateListRecipients(tenant, id, dto.recipients, auditActor(actor, req))
+  }
+
+  @Delete('lists/:id')
+  @HttpCode(204)
+  async deleteList(
+    @Param('slug') slug: string,
+    @Param('id') id: string,
+    @CurrentUser() jwt: AuthentikJwtPayload,
+    @Req() req: Parameters<typeof clientIp>[0],
+  ) {
+    const { actor, tenant } = await this.gate(slug, jwt)
+    await this.mail.deleteList(tenant, id, auditActor(actor, req))
+  }
+}
diff --git a/services/platform-api/src/mail/mail.module.ts b/services/platform-api/src/mail/mail.module.ts
new file mode 100644
index 0000000..2aa45dd
--- /dev/null
+++ b/services/platform-api/src/mail/mail.module.ts
@@ -0,0 +1,26 @@
+import { Module } from '@nestjs/common'
+import { MongooseModule } from '@nestjs/mongoose'
+import { AuditModule } from '../audit/audit.module.js'
+import { AuthModule } from '../auth/auth.module.js'
+import { IntegrationsModule } from '../integrations/integrations.module.js'
+import { Domain, DomainSchema } from '../schemas/domain.schema.js'
+import { User, UserSchema } from '../schemas/user.schema.js'
+import { TenantsModule } from '../tenants/tenants.module.js'
+import { MailController } from './mail.controller.js'
+import { MailService } from './mail.service.js'
+
+@Module({
+  imports: [
+    MongooseModule.forFeature([
+      { name: Domain.name, schema: DomainSchema },
+      { name: User.name, schema: UserSchema },
+    ]),
+    AuthModule,
+    AuditModule,
+    IntegrationsModule,
+    TenantsModule, // TenantsService — resolve tenant by slug for the membership gate
+  ],
+  controllers: [MailController],
+  providers: [MailService],
+})
+export class MailModule {}
diff --git a/services/platform-api/src/mail/mail.service.ts b/services/platform-api/src/mail/mail.service.ts
new file mode 100644
index 0000000..dc1fd0c
--- /dev/null
+++ b/services/platform-api/src/mail/mail.service.ts
@@ -0,0 +1,243 @@
+import { BadRequestException, Injectable, NotFoundException } from '@nestjs/common'
+import { InjectModel } from '@nestjs/mongoose'
+import { Model, Types } from 'mongoose'
+import { AuditService, type AuditActor } from '../audit/audit.service.js'
+import { StalwartClient } from '../integrations/stalwart.client.js'
+import { Domain, DomainDocument } from '../schemas/domain.schema.js'
+import { User, UserDocument } from '../schemas/user.schema.js'
+
+// Tenant-scoped view of the bits of Stalwart mail config that are per-customer:
+// aliases (extra addresses on a mailbox) and distribution lists. Both are keyed
+// to one of the tenant's domains, so they're naturally isolated per workspace.
+
+export interface AliasView {
+  address: string // localPart@domain
+  localPart: string
+  domain: string
+  destination: string // the mailbox it delivers to
+  accountId: string // Stalwart account holding the alias
+  enabled: boolean
+}
+
+export interface ListView {
+  id: string
+  name: string
+  address: string
+  domain: string
+  recipients: string[]
+  members: number
+  description?: string
+}
+
+export interface TenantRef {
+  _id: Types.ObjectId
+  slug: string
+}
+
+@Injectable()
+export class MailService {
+  constructor(
+    @InjectModel(Domain.name) private readonly domainModel: Model<DomainDocument>,
+    @InjectModel(User.name) private readonly userModel: Model<UserDocument>,
+    private readonly stalwart: StalwartClient,
+    private readonly audit: AuditService,
+  ) {}
+
+  // Maps between a tenant's domain names and their Stalwart domain ids, both ways.
+  private async tenantDomains(
+    tenantId: Types.ObjectId,
+  ): Promise<{ byStalwartId: Map<string, string>; byName: Map<string, string> }> {
+    const domains = await this.domainModel
+      .find({ tenantId, stalwartId: { $exists: true } }, { domain: 1, stalwartId: 1 })
+      .exec()
+    const byStalwartId = new Map<string, string>()
+    const byName = new Map<string, string>()
+    for (const d of domains) {
+      if (d.stalwartId) {
+        byStalwartId.set(d.stalwartId, d.domain)
+        byName.set(d.domain, d.stalwartId)
+      }
+    }
+    return { byStalwartId, byName }
+  }
+
+  // ── Aliases ────────────────────────────────────────────────────────────────
+
+  async listAliases(tenant: TenantRef): Promise<AliasView[]> {
+    if (!this.stalwart.configured) return []
+    const { byStalwartId } = await this.tenantDomains(tenant._id)
+    if (byStalwartId.size === 0) return []
+    const accounts = await this.stalwart.listAccountsWithAliases()
+    const out: AliasView[] = []
+    for (const acc of accounts) {
+      for (const a of acc.aliases) {
+        const domain = byStalwartId.get(a.domainId)
+        if (!domain) continue // alias on a domain this tenant doesn't own
+        out.push({
+          address: `${a.name}@${domain}`,
+          localPart: a.name,
+          domain,
+          destination: acc.emailAddress,
+          accountId: acc.id,
+          enabled: a.enabled,
+        })
+      }
+    }
+    return out.sort((x, y) => x.address.localeCompare(y.address))
+  }
+
+  async createAlias(
+    tenant: TenantRef,
+    dto: { localPart: string; domain: string; destinationUserId: string },
+    actor: AuditActor,
+  ): Promise<AliasView> {
+    const { byName } = await this.tenantDomains(tenant._id)
+    const domain = dto.domain.trim().toLowerCase()
+    const domainStalwartId = byName.get(domain)
+    if (!domainStalwartId) {
+      throw new BadRequestException(`Domain "${domain}" isn't part of this workspace.`)
+    }
+    const localPart = dto.localPart.trim().toLowerCase()
+    const dest = await this.userModel
+      .findOne({ _id: dto.destinationUserId, tenantIds: tenant._id })
+      .exec()
+    if (!dest?.stalwartAccountId) {
+      throw new BadRequestException('The destination must be a mailbox user in this workspace.')
+    }
+    await this.stalwart.addAlias(dest.stalwartAccountId, localPart, domainStalwartId)
+    const address = `${localPart}@${domain}`
+    await this.audit.record(
+      {
+        action: 'mail.alias_created',
+        resourceType: 'system',
+        resourceId: address,
+        resourceName: address,
+        tenantSlug: tenant.slug,
+        metadata: { destination: dest.email },
+      },
+      actor,
+    )
+    return { address, localPart, domain, destination: dest.email, accountId: dest.stalwartAccountId, enabled: true }
+  }
+
+  async deleteAlias(tenant: TenantRef, address: string, actor: AuditActor): Promise<void> {
+    const target = address.trim().toLowerCase()
+    const match = (await this.listAliases(tenant)).find((a) => a.address === target)
+    if (!match) throw new NotFoundException(`Alias "${address}" not found.`)
+    const { byName } = await this.tenantDomains(tenant._id)
+    await this.stalwart.removeAlias(match.accountId, match.localPart, byName.get(match.domain)!)
+    await this.audit.record(
+      {
+        action: 'mail.alias_deleted',
+        resourceType: 'system',
+        resourceId: target,
+        resourceName: target,
+        tenantSlug: tenant.slug,
+      },
+      actor,
+    )
+  }
+
+  // ── Distribution lists ───────────────────────────────────────────────────────
+
+  async listLists(tenant: TenantRef): Promise<ListView[]> {
+    if (!this.stalwart.configured) return []
+    const { byStalwartId } = await this.tenantDomains(tenant._id)
+    if (byStalwartId.size === 0) return []
+    const lists = await this.stalwart.listMailingLists()
+    return lists
+      .filter((l) => byStalwartId.has(l.domainId))
+      .map((l) => ({
+        id: l.id,
+        name: l.name,
+        address: l.emailAddress || `${l.name}@${byStalwartId.get(l.domainId)}`,
+        domain: byStalwartId.get(l.domainId)!,
+        recipients: l.recipients,
+        members: l.recipients.length,
+        description: l.description,
+      }))
+      .sort((x, y) => x.address.localeCompare(y.address))
+  }
+
+  async createList(
+    tenant: TenantRef,
+    dto: { localPart: string; domain: string; recipients?: string[]; description?: string },
+    actor: AuditActor,
+  ): Promise<ListView> {
+    const { byName } = await this.tenantDomains(tenant._id)
+    const domain = dto.domain.trim().toLowerCase()
+    const domainStalwartId = byName.get(domain)
+    if (!domainStalwartId) {
+      throw new BadRequestException(`Domain "${domain}" isn't part of this workspace.`)
+    }
+    const localPart = dto.localPart.trim().toLowerCase()
+    const recipients = cleanRecipients(dto.recipients)
+    const { id } = await this.stalwart.createMailingList({
+      domainId: domainStalwartId,
+      name: localPart,
+      recipients,
+      description: dto.description,
+    })
+    const address = `${localPart}@${domain}`
+    await this.audit.record(
+      {
+        action: 'mail.list_created',
+        resourceType: 'system',
+        resourceId: address,
+        resourceName: address,
+        tenantSlug: tenant.slug,
+        metadata: { members: recipients.length },
+      },
+      actor,
+    )
+    return { id, name: localPart, address, domain, recipients, members: recipients.length, description: dto.description }
+  }
+
+  async updateListRecipients(
+    tenant: TenantRef,
+    id: string,
+    recipients: string[],
+    actor: AuditActor,
+  ): Promise<ListView> {
+    const list = await this.assertListInTenant(tenant, id)
+    const clean = cleanRecipients(recipients)
+    await this.stalwart.updateMailingListRecipients(id, clean)
+    await this.audit.record(
+      {
+        action: 'mail.list_updated',
+        resourceType: 'system',
+        resourceId: list.address,
+        resourceName: list.address,
+        tenantSlug: tenant.slug,
+        metadata: { members: clean.length },
+      },
+      actor,
+    )
+    return { ...list, recipients: clean, members: clean.length }
+  }
+
+  async deleteList(tenant: TenantRef, id: string, actor: AuditActor): Promise<void> {
+    const list = await this.assertListInTenant(tenant, id)
+    await this.stalwart.deleteMailingList(id)
+    await this.audit.record(
+      {
+        action: 'mail.list_deleted',
+        resourceType: 'system',
+        resourceId: list.address,
+        resourceName: list.address,
+        tenantSlug: tenant.slug,
+      },
+      actor,
+    )
+  }
+
+  private async assertListInTenant(tenant: TenantRef, id: string): Promise<ListView> {
+    const list = (await this.listLists(tenant)).find((l) => l.id === id)
+    if (!list) throw new NotFoundException('Distribution list not found in this workspace.')
+    return list
+  }
+}
+
+function cleanRecipients(recipients?: string[]): string[] {
+  return [...new Set((recipients ?? []).map((r) => r.trim().toLowerCase()).filter(Boolean))]
+}