feat(postbox): enforce unified inbox separation

2026-08-20 04:22:29 +02:00
parent 174ee97719
commit 41ea8d8e23
16 changed files with 1029 additions and 25 deletions
@@ -45,6 +45,7 @@ export type PostboxDirectoryItem = {
  key_epoch: number;
  encryption_vault_id?: string | null;
  protection_policy: PostboxProtectionPolicy;
+  grouping_policy: PostboxGroupingPolicy;
  access?: PostboxAccessDecision | null;
  resource_revision: number;
  etag: string;
@@ -74,6 +75,11 @@ export type PostboxProtectionPolicy = {
  vacancy_escalation_content_access: "metadata_only";
 };

+export type PostboxGroupingPolicy = {
+  mode: "allow" | "same_classification" | "separate";
+  reason?: string | null;
+};
+
 export type PostboxProtectionProfile = {
  id: PostboxProtectionProfileId;
  label: string;
@@ -200,6 +206,13 @@ export type PostboxGrouping = {
  postbox_ids: string[];
  total_count: number;
  unread_count: number;
+  constraints: Array<{
+    code: "source_requires_separation" | "classification_separation_required";
+    mode: PostboxGroupingPolicy["mode"];
+    postbox_id: string;
+    reason?: string | null;
+    enforced_by: "postbox_configuration";
+  }>;
  resource_revision: number;
  etag: string;
  created_at: string;
@@ -288,6 +301,7 @@ export type PostboxTemplateRevision = {
  encryption_profile: string;
  encryption_vault_id?: string | null;
  protection_policy: PostboxProtectionPolicy;
+  grouping_policy: PostboxGroupingPolicy;
  history_policy: Record<string, unknown>;
  routing_policy: PostboxRoutingPolicy;
  retention_policy: Record<string, unknown>;
@@ -326,6 +340,7 @@ export type PostboxTemplateRevisionPayload = Pick<
  | "encryption_profile"
  | "encryption_vault_id"
  | "protection_policy"
+  | "grouping_policy"
  | "routing_policy"
 >;

@@ -371,6 +386,7 @@ export type PostboxExactCreatePayload = {
  encryption_profile: PostboxProtectionProfileId;
  encryption_vault_id?: string | null;
  protection_policy: PostboxProtectionPolicy;
+  grouping_policy: PostboxGroupingPolicy;
 };

 export type PostboxMessageAuthoringPayload = {
@@ -613,6 +629,25 @@ export function updatePostboxProtectionPolicy(
  );
 }

+export function updatePostboxGroupingPolicy(
+  settings: ApiSettings,
+  postbox: PostboxDirectoryItem,
+  groupingPolicy: PostboxGroupingPolicy
+): Promise<PostboxDirectoryItem> {
+  return apiFetch(
+    settings,
+    `/api/v1/postbox/admin/postboxes/${encodeURIComponent(postbox.id)}/grouping-policy`,
+    {
+      method: "PUT",
+      headers: { "If-Match": postbox.etag },
+      body: JSON.stringify({
+        base_revision: postbox.resource_revision,
+        grouping_policy: groupingPolicy
+      })
+    }
+  );
+}
+
 export async function listPostboxOrganizationTargets(
  settings: ApiSettings
 ): Promise<PostboxOrganizationTargets> {
@@ -51,8 +51,10 @@ import {
  retirePostboxTemplate,
  revisePostboxTemplate,
  updatePostboxProtectionPolicy,
+  updatePostboxGroupingPolicy,
  type PostboxDirectoryItem,
  type PostboxExactCreatePayload,
+  type PostboxGroupingPolicy,
  type PostboxOrganizationFunction,
  type PostboxOrganizationStructure,
  type PostboxOrganizationUnit,
@@ -114,6 +116,11 @@ const protectionPolicyDefaults = (): PostboxProtectionPolicy => ({
  vacancy_escalation_content_access: "metadata_only"
 });

+const groupingPolicyDefaults = (): PostboxGroupingPolicy => ({
+  mode: "allow",
+  reason: null
+});
+
 const routingDefaults = (): PostboxRoutingPolicy => ({
  linked_copy: {
    enabled: false,
@@ -157,6 +164,7 @@ const templateDefaults = (): TemplateDraft => ({
  encryption_profile: "server_envelope_v1",
  encryption_vault_id: "",
  protection_policy: protectionPolicyDefaults(),
+  grouping_policy: groupingPolicyDefaults(),
  routing_policy: routingDefaults()
 });

@@ -170,7 +178,8 @@ const exactDefaults = (): ExactDraft => ({
  portal_visible: false,
  encryption_profile: "server_envelope_v1",
  encryption_vault_id: "",
-  protection_policy: protectionPolicyDefaults()
+  protection_policy: protectionPolicyDefaults(),
+  grouping_policy: groupingPolicyDefaults()
 });

 const protectionTransitionDefaults = (
@@ -248,6 +257,9 @@ export default function PostboxAdminPanel({
  const [policyDialogOpen, setPolicyDialogOpen] = useState(false);
  const [policyDraft, setPolicyDraft] = useState<PostboxProtectionPolicy>(protectionPolicyDefaults);
  const [policyBaseline, setPolicyBaseline] = useState<PostboxProtectionPolicy>(protectionPolicyDefaults);
+  const [groupingPolicyDialogOpen, setGroupingPolicyDialogOpen] = useState(false);
+  const [groupingPolicyDraft, setGroupingPolicyDraft] = useState<PostboxGroupingPolicy>(groupingPolicyDefaults);
+  const [groupingPolicyBaseline, setGroupingPolicyBaseline] = useState<PostboxGroupingPolicy>(groupingPolicyDefaults);
  const { requestDiscard } = useUnsavedChanges();

  const selectedTemplate = useMemo(
@@ -283,9 +295,11 @@ export default function PostboxAdminPanel({
  const materializeDirty = materializeDialogOpen && draftKey(materializeDraft) !== draftKey(materializeBaseline);
  const protectionDirty = protectionDialogOpen && draftKey(protectionDraft) !== draftKey(protectionBaseline);
  const policyDirty = policyDialogOpen && draftKey(policyDraft) !== draftKey(policyBaseline);
+  const groupingPolicyDirty = groupingPolicyDialogOpen
+    && draftKey(groupingPolicyDraft) !== draftKey(groupingPolicyBaseline);

  useUnsavedDraftGuard({
-    dirty: templateDirty || exactDirty || materializeDirty || protectionDirty || policyDirty,
+    dirty: templateDirty || exactDirty || materializeDirty || protectionDirty || policyDirty || groupingPolicyDirty,
    title: "Unsaved Postbox administration draft",
    message: "Save or discard the open Postbox administration draft before leaving this surface.",
    onSave: saveActiveDraft,
@@ -375,6 +389,7 @@ export default function PostboxAdminPanel({
      encryption_profile: revision.encryption_profile,
      encryption_vault_id: revision.encryption_vault_id ?? "",
      protection_policy: revision.protection_policy ?? protectionPolicyDefaults(),
+      grouping_policy: revision.grouping_policy ?? groupingPolicyDefaults(),
      routing_policy: revision.routing_policy ?? routingDefaults()
    };
    setTemplatePreview(null);
@@ -581,6 +596,38 @@ export default function PostboxAdminPanel({
    }
  }

+  function openGroupingPolicy() {
+    if (!selectedPostbox) return;
+    const next = selectedPostbox.grouping_policy || groupingPolicyDefaults();
+    setGroupingPolicyDraft(next);
+    setGroupingPolicyBaseline(next);
+    setGroupingPolicyDialogOpen(true);
+  }
+
+  async function saveGroupingPolicy(): Promise<boolean> {
+    if (!selectedPostbox) return false;
+    setBusy(true);
+    setError("");
+    setSuccess("");
+    try {
+      await updatePostboxGroupingPolicy(
+        settings,
+        selectedPostbox,
+        groupingPolicyDraft
+      );
+      setGroupingPolicyBaseline(groupingPolicyDraft);
+      setGroupingPolicyDialogOpen(false);
+      setSuccess("Unified-inbox separation policy updated.");
+      await load();
+      return true;
+    } catch (actionError) {
+      setError(errorMessage(actionError));
+      return false;
+    } finally {
+      setBusy(false);
+    }
+  }
+
  function openMaterialize(template: PostboxTemplate) {
    const revision = currentRevision(template);
    const compatible = compatibleTargets(units, revision?.function_type_id);
@@ -660,6 +707,7 @@ export default function PostboxAdminPanel({
    if (materializeDirty) return materialize();
    if (protectionDirty) return saveProtectionTransition();
    if (policyDirty) return saveProtectionPolicy();
+    if (groupingPolicyDirty) return saveGroupingPolicy();
    return Promise.resolve(true);
  }

@@ -684,6 +732,10 @@ export default function PostboxAdminPanel({
      setPolicyDraft(policyBaseline);
      setPolicyDialogOpen(false);
    }
+    if (groupingPolicyDialogOpen) {
+      setGroupingPolicyDraft(groupingPolicyBaseline);
+      setGroupingPolicyDialogOpen(false);
+    }
  }

  function closeTemplateDialog() {
@@ -731,6 +783,15 @@ export default function PostboxAdminPanel({
    else close();
  }

+  function closeGroupingPolicyDialog() {
+    const close = () => {
+      setGroupingPolicyDraft(groupingPolicyBaseline);
+      setGroupingPolicyDialogOpen(false);
+    };
+    if (groupingPolicyDirty) requestDiscard(close);
+    else close();
+  }
+
  return (
    <AdminPageLayout
      title="Postboxes"
@@ -807,6 +868,7 @@ export default function PostboxAdminPanel({
          onSelect={setSelectedPostboxId}
          onChangeProtection={openProtectionTransition}
          onEditPolicy={openProtectionPolicy}
+          onEditGroupingPolicy={openGroupingPolicy}
          onArchive={setArchiveTarget}
          busy={busy}
        />
@@ -872,6 +934,15 @@ export default function PostboxAdminPanel({
        onClose={closePolicyDialog}
        onSave={() => void saveProtectionPolicy()}
      />
+      <GroupingPolicyDialog
+        open={groupingPolicyDialogOpen}
+        postbox={selectedPostbox}
+        draft={groupingPolicyDraft}
+        busy={busy}
+        onChange={setGroupingPolicyDraft}
+        onClose={closeGroupingPolicyDialog}
+        onSave={() => void saveGroupingPolicy()}
+      />
      <ConfirmDialog
        open={Boolean(archiveTarget)}
        title="Archive Postbox"
@@ -1051,6 +1122,7 @@ function PostboxWorkspace({
  onSelect,
  onChangeProtection,
  onEditPolicy,
+  onEditGroupingPolicy,
  onArchive,
  busy
 }: {
@@ -1060,6 +1132,7 @@ function PostboxWorkspace({
  onSelect: (id: string) => void;
  onChangeProtection: () => void;
  onEditPolicy: () => void;
+  onEditGroupingPolicy: () => void;
  onArchive: (postbox: PostboxDirectoryItem) => void;
  busy: boolean;
 }) {
@@ -1104,6 +1177,13 @@ function PostboxWorkspace({
                >
                  <Pencil size={16} /> Edit policy
                </Button>
+                <Button
+                  onClick={onEditGroupingPolicy}
+                  disabled={busy || selected.status !== "active"}
+                  disabledReason={postboxBusyReason(false, busy) ?? (selected.status !== "active" ? POSTBOX_INTERFACE_I18N.archivedPostbox : undefined)}
+                >
+                  <Boxes size={16} /> Inbox separation
+                </Button>
                <Button
                  onClick={onChangeProtection}
                  disabled={busy || selected.status !== "active"}
@@ -1134,6 +1214,7 @@ function PostboxWorkspace({
              <div><dt>Key epoch</dt><dd>{selected.key_epoch}</dd></div>
              <div><dt>New incumbent history</dt><dd>{selected.protection_policy.new_incumbent_history.replaceAll("_", " ")}</dd></div>
              <div><dt>External recipient assurance</dt><dd>{selected.protection_policy.external_recipient_assurance.replaceAll("_", " ")}</dd></div>
+              <div><dt>Unified-inbox policy</dt><dd>{selected.grouping_policy.mode.replaceAll("_", " ")}</dd></div>
            </dl>
            {transitions.length ? (
              <div className="postbox-revision-history">
@@ -1435,6 +1516,10 @@ function TemplateDialog({
            protection_policy
          })}
        />
+        <GroupingPolicyFields
+          policy={draft.grouping_policy}
+          onChange={(grouping_policy) => onChange({ ...draft, grouping_policy })}
+        />
        <div className="postbox-routing-section">
          <div className="postbox-routing-heading">
            <div>
@@ -1825,6 +1910,10 @@ function ExactPostboxDialog({
            protection_policy
          })}
        />
+        <GroupingPolicyFields
+          policy={draft.grouping_policy}
+          onChange={(grouping_policy) => onChange({ ...draft, grouping_policy })}
+        />
      </FormGrid>
    </Dialog>
  );
@@ -2054,6 +2143,51 @@ function AuthorityField({
  );
 }

+function GroupingPolicyFields({
+  policy,
+  onChange
+}: {
+  policy: PostboxGroupingPolicy;
+  onChange: (policy: PostboxGroupingPolicy) => void;
+}) {
+  return (
+    <div className="postbox-protection-section">
+      <div className="postbox-routing-heading">
+        <div>
+          <strong>Unified-inbox separation</strong>
+          <span>Keep source containers and institutional responsibilities visibly separated where required.</span>
+          <DocumentationHelpLink reference={POSTBOX_FIELD_DOCUMENTATION} />
+        </div>
+      </div>
+      <FormGrid>
+        <FormField label="Grouping rule" documentation={POSTBOX_FIELD_DOCUMENTATION}>
+          <select
+            value={policy.mode}
+            onChange={(event) => onChange({
+              ...policy,
+              mode: event.target.value as PostboxGroupingPolicy["mode"]
+            })}
+          >
+            <option value="allow">May be combined</option>
+            <option value="same_classification">Only with the same classification</option>
+            <option value="separate">Always keep this Postbox separate</option>
+          </select>
+        </FormField>
+        <FormField label="Explanation" documentation={POSTBOX_FIELD_DOCUMENTATION}>
+          <input
+            value={policy.reason || ""}
+            placeholder="Why this separation is required"
+            onChange={(event) => onChange({
+              ...policy,
+              reason: event.target.value || null
+            })}
+          />
+        </FormField>
+      </FormGrid>
+    </div>
+  );
+}
+
 function QuorumField({
  label,
  value,
@@ -2130,6 +2264,47 @@ function ProtectionPolicyDialog({
  );
 }

+function GroupingPolicyDialog({
+  open,
+  postbox,
+  draft,
+  busy,
+  onChange,
+  onClose,
+  onSave
+}: {
+  open: boolean;
+  postbox: PostboxDirectoryItem | null;
+  draft: PostboxGroupingPolicy;
+  busy: boolean;
+  onChange: (policy: PostboxGroupingPolicy) => void;
+  onClose: () => void;
+  onSave: () => void;
+}) {
+  return (
+    <Dialog
+      open={open}
+      title={postbox ? `Unified-inbox policy for ${postbox.name}` : "Unified-inbox policy"}
+      className="postbox-dialog"
+      onClose={onClose}
+      closeDisabled={busy}
+      footer={
+        <div className="button-row compact-actions">
+          <Button onClick={onClose} disabled={busy} disabledReason={postboxBusyReason(false, busy)}>Cancel</Button>
+          <Button variant="primary" onClick={onSave} disabled={busy} disabledReason={postboxBusyReason(false, busy)}>
+            <Save size={16} /> Save separation policy
+          </Button>
+        </div>
+      }
+    >
+      <GroupingPolicyFields policy={draft} onChange={onChange} />
+      <p className="postbox-form-note">
+        The rule is evaluated whenever a personal grouping or aggregate message projection is used. Existing preferences are retained, but a newly enforced rule prevents an unsafe combined projection and explains its configured source.
+      </p>
+    </Dialog>
+  );
+}
+
 function ProtectionTransitionDialog({
  open,
  postbox,
@@ -2435,6 +2610,7 @@ function revisionPayload(draft: TemplateDraft): PostboxTemplateRevisionPayload {
      ? draft.encryption_vault_id?.trim() || null
      : null,
    protection_policy: draft.protection_policy,
+    grouping_policy: draft.grouping_policy,
    routing_policy: draft.routing_policy
  };
 }
@@ -29,17 +29,22 @@ export default function PostboxInboxWidget({
  const maxItems = numberSetting(configuration.maxItems, 5, 1, 12);
  const load = useCallback(async () => {
    const postboxes = await listPostboxes(settings);
-    if (!postboxes.length) {
-      return { messages: [], total: 0 };
+    const eligible = postboxes.filter(
+      (postbox) => postbox.grouping_policy.mode === "allow"
+    );
+    const separatedCount = postboxes.length - eligible.length;
+    if (!eligible.length) {
+      return { messages: [], total: 0, separatedCount };
    }
-    return listPostboxMessages(
+    const response = await listPostboxMessages(
      settings,
-      postboxes.map((postbox) => postbox.id),
+      eligible.map((postbox) => postbox.id),
      maxItems,
      0,
      "",
      "unread"
    );
+    return { ...response, separatedCount };
  }, [maxItems, settings]);
  const { data, loading, error } = useDashboardWidgetData(load, refreshKey);

@@ -50,6 +55,11 @@ export default function PostboxInboxWidget({
          {error}
        </DismissibleAlert>
      )}
+      {data?.separatedCount ? (
+        <DismissibleAlert tone="info" dismissible={false}>
+          {data.separatedCount} governed Postbox source{data.separatedCount === 1 ? " is" : "s are"} shown only in separated inbox views.
+        </DismissibleAlert>
+      ) : null}
      <DashboardWidgetList
        emptyText="No unread Postbox messages."
        items={(data?.messages ?? []).map((message) => ({
@@ -119,6 +119,9 @@ export default function PostboxPage({
  const requestedPostboxId = useRef(
    new URLSearchParams(location.search).get("postbox") ?? ""
  );
+  const requestedGroupingId = useRef(
+    new URLSearchParams(location.search).get("grouping") ?? ""
+  );
  const requestedMessageLoaded = useRef(false);
  const requestedComposeLoaded = useRef(false);
  const [postboxes, setPostboxes] = useState<PostboxDirectoryItem[]>([]);
@@ -176,6 +179,14 @@ export default function PostboxPage({
    }
    return postboxes.map((postbox) => postbox.id);
  }, [postboxes, selectedGrouping, selectedPostboxId]);
+  const scopeSeparationConflict = useMemo(
+    () => selectedPostboxId ? null : groupingConflict(postboxes, scopePostboxIds),
+    [postboxes, scopePostboxIds, selectedPostboxId]
+  );
+  const groupingDraftConflict = useMemo(
+    () => groupingConflict(postboxes, groupingDraft.postbox_ids),
+    [groupingDraft.postbox_ids, postboxes]
+  );
  const scopeKey = scopePostboxIds.join("|");
  const composeDisabledReason = postboxBusyReason(false, busy)
    ?? (!canSend ? POSTBOX_INTERFACE_I18N.noSendReason : undefined)
@@ -218,6 +229,9 @@ export default function PostboxPage({
      setPostboxes(nextPostboxes);
      setGroupings(nextGroupings);
      setSelectedScope((current) => {
+        if (nextGroupings.some((grouping) => grouping.id === requestedGroupingId.current)) {
+          return requestedGroupingId.current;
+        }
        if (current === "all" || nextGroupings.some((grouping) => grouping.id === current)) {
          return current;
        }
@@ -238,7 +252,7 @@ export default function PostboxPage({
  }, [settings]);

  const loadMessages = useCallback(async () => {
-    if (!scopePostboxIds.length) {
+    if (!scopePostboxIds.length || scopeSeparationConflict) {
      setMessages([]);
      setSelectedMessageId("");
      setSelectedMessage(null);
@@ -274,7 +288,7 @@ export default function PostboxPage({
    } finally {
      setLoadingMessages(false);
    }
-  }, [messageQuery, messageState, page, pageSize, scopeKey, settings]);
+  }, [messageQuery, messageState, page, pageSize, scopeKey, scopeSeparationConflict, settings]);

  useEffect(() => {
    void loadDirectory();
@@ -440,12 +454,22 @@ export default function PostboxPage({
  }

  function selectScope(scopeId: string) {
+    requestedGroupingId.current = scopeId === "all" ? "" : scopeId;
    setSelectedScope(scopeId);
    setSelectedPostboxId("");
    setPage(1);
    setSelectedMessageId("");
    setSelectedMessage(null);
    setUnavailableSelection("");
+    const parameters = new URLSearchParams(location.search);
+    if (scopeId === "all") parameters.delete("grouping");
+    else parameters.set("grouping", scopeId);
+    parameters.delete("postbox");
+    const search = parameters.toString();
+    navigate(
+      { pathname: location.pathname, search: search ? `?${search}` : "" },
+      { replace: true, state: location.state }
+    );
  }

  function openNewGrouping() {
@@ -469,6 +493,10 @@ export default function PostboxPage({

  async function saveGrouping(): Promise<boolean> {
    if (!groupingDraft.name.trim()) return false;
+    if (groupingDraftConflict) {
+      setError(groupingDraftConflict);
+      return false;
+    }
    setBusy(true);
    setError("");
    const payload = {
@@ -482,8 +510,7 @@ export default function PostboxPage({
        ? await updatePostboxGrouping(settings, existing, payload)
        : await createPostboxGrouping(settings, payload);
      await loadDirectory();
-      setSelectedScope(saved.id);
-      setSelectedPostboxId("");
+      selectScope(saved.id);
      setGroupingDialogOpen(false);
      setGroupingBaseline(groupingDraft);
      return true;
@@ -503,8 +530,7 @@ export default function PostboxPage({
      const existing = groupings.find((item) => item.id === deleteGroupingTarget.id);
      if (!existing) throw new Error("The grouping is no longer available.");
      await deletePostboxGrouping(settings, existing);
-      setSelectedScope("all");
-      setSelectedPostboxId("");
+      selectScope("all");
      setGroupingDialogOpen(false);
      setDeleteGroupingTarget(null);
      await loadDirectory();
@@ -693,6 +719,19 @@ export default function PostboxPage({
                />
              ) : null}
            </div>
+            {scopeSeparationConflict ? (
+              <DismissibleAlert tone="warning" dismissible={false}>
+                <strong>Combined view unavailable.</strong>{" "}
+                {scopeSeparationConflict} Select one source Postbox or edit the unified view.
+              </DismissibleAlert>
+            ) : selectedGrouping?.constraints.length ? (
+              <DismissibleAlert tone="info" dismissible={false}>
+                This projection is governed by {selectedGrouping.constraints.length} source-separation rule{selectedGrouping.constraints.length === 1 ? "" : "s"}.
+                {selectedGrouping.constraints.find((item) => item.reason)?.reason
+                  ? ` ${selectedGrouping.constraints.find((item) => item.reason)?.reason}`
+                  : ""}
+              </DismissibleAlert>
+            ) : null}
          </div>

          <div className="postbox-directory-list">
@@ -972,8 +1011,11 @@ export default function PostboxPage({
              <Button
                variant="primary"
                onClick={() => void saveGrouping()}
-                disabled={busy || !groupingDraft.name.trim()}
-                disabledReason={postboxBusyReason(false, busy) ?? (!groupingDraft.name.trim() ? POSTBOX_INTERFACE_I18N.incompleteDraft : undefined)}
+                disabled={busy || !groupingDraft.name.trim() || Boolean(groupingDraftConflict)}
+                disabledReason={postboxBusyReason(false, busy)
+                  ?? (!groupingDraft.name.trim() ? POSTBOX_INTERFACE_I18N.incompleteDraft : undefined)
+                  ?? groupingDraftConflict
+                  ?? undefined}
              >
                Save
              </Button>
@@ -1013,6 +1055,13 @@ export default function PostboxPage({
              <input
                type="checkbox"
                checked={groupingDraft.postbox_ids.includes(postbox.id)}
+                disabled={
+                  !groupingDraft.postbox_ids.includes(postbox.id)
+                  && Boolean(groupingConflict(
+                    postboxes,
+                    [...groupingDraft.postbox_ids, postbox.id]
+                  ))
+                }
                onChange={(event) =>
                  setGroupingDraft((current) => ({
                    ...current,
@@ -1025,10 +1074,21 @@ export default function PostboxPage({
              <span>
                <strong>{postbox.name}</strong>
                <small>{postbox.organization_unit_name} · {postbox.function_name}</small>
+                {postbox.grouping_policy.mode !== "allow" ? (
+                  <small>
+                    {postbox.grouping_policy.reason
+                      || postbox.grouping_policy.mode.replaceAll("_", " ")}
+                  </small>
+                ) : null}
              </span>
            </label>
          ))}
        </fieldset>
+        {groupingDraftConflict ? (
+          <DismissibleAlert tone="warning" dismissible={false}>
+            {groupingDraftConflict}
+          </DismissibleAlert>
+        ) : null}
      </Dialog>

      <Dialog
@@ -1304,6 +1364,34 @@ function attachmentResolutionExplanation(reasonCode: string): string {
  return explanations[reasonCode] || "The referenced payload cannot currently be opened.";
 }

+function groupingConflict(
+  postboxes: PostboxDirectoryItem[],
+  postboxIds: string[]
+): string | null {
+  const selected = postboxIds
+    .map((postboxId) => postboxes.find((postbox) => postbox.id === postboxId))
+    .filter((postbox): postbox is PostboxDirectoryItem => Boolean(postbox));
+  if (selected.length <= 1) return null;
+  const separate = selected.find(
+    (postbox) => postbox.grouping_policy.mode === "separate"
+  );
+  if (separate) {
+    return separate.grouping_policy.reason
+      || `${separate.name} must remain a separate inbox.`;
+  }
+  const classificationRule = selected.find(
+    (postbox) => postbox.grouping_policy.mode === "same_classification"
+  );
+  if (
+    classificationRule
+    && new Set(selected.map((postbox) => postbox.classification)).size > 1
+  ) {
+    return classificationRule.grouping_policy.reason
+      || "These Postboxes cannot be combined across classifications.";
+  }
+  return null;
+}
+
 function sourceName(
  postboxes: PostboxDirectoryItem[],
  postboxId: string
@@ -39,16 +39,22 @@ export default function PostboxQuickAccess({
  const [selectedId, setSelectedId] = useState("");
  const load = useCallback(async () => {
    const postboxes = await listPostboxes(settings);
-    if (!postboxes.length) return { postboxes, messages: [], total: 0 };
+    const eligible = postboxes.filter(
+      (postbox) => postbox.grouping_policy.mode === "allow"
+    );
+    const separatedCount = postboxes.length - eligible.length;
+    if (!eligible.length) {
+      return { postboxes, messages: [], total: 0, separatedCount };
+    }
    const response = await listPostboxMessages(
      settings,
-      postboxes.map((postbox) => postbox.id),
+      eligible.map((postbox) => postbox.id),
      MESSAGE_LIMIT,
      0,
      "",
      "unread"
    );
-    return { postboxes, ...response };
+    return { postboxes, separatedCount, ...response };
  }, [settings]);
  const { data, loading, error } = useDashboardWidgetData(load, 0);
  const messages = data?.messages ?? [];
@@ -93,6 +99,11 @@ export default function PostboxQuickAccess({
        </p>
      ) : null}
      {error ? <DismissibleAlert tone="warning" resetKey={error}>{error}</DismissibleAlert> : null}
+      {data?.separatedCount ? (
+        <DismissibleAlert tone="info" dismissible={false}>
+          {data.separatedCount} Postbox source{data.separatedCount === 1 ? " is" : "s are"} available only in a separated inbox view.
+        </DismissibleAlert>
+      ) : null}

      {messages.length ? (
        <SelectionList variant="navigation" label="i18n:govoplan-postbox.quick_unread_messages">