@@ -0,0 +1,15 @@
+---
+'@objectstack/service-automation': patch
+---
+
+fix(service-automation): a `notify` node naming `email` and another channel mails an address no user holds and no longer writes an inbox row addressed to it
+
+Clause-②: no
+Metadata-protocol: none
+
+An email address written out in `recipients` is the author's constant: on a node whose `channels` name `email` it is mailed as written. The inbox delivers to a user, keying its row by the recipient as a user id, and so does every channel but `email`. So on a node whose `channels` name `email` and another channel, such as `['inbox', 'email']`, an address no user holds now goes to the email channel alone.
+
+- **Fixed.** Before, the address went to every channel as it stood: the email channel mailed it, and the inbox also wrote a `sys_inbox_message` row whose `user_id` was the address, which no inbox reads. Now the node emits that address apart, on the `email` channel only, and the inbox writes no row for it. `user:ADDRESS` is handled the same way, whoever holds the address, because `user:` hands the address on as the user id with no lookup. An address whose holder cannot be looked up (no data engine, a lookup that fails) is mailed alone too.
+- **Unchanged.** The node succeeds as before. An address a user holds, written bare, still reaches that user's inbox and is mailed. A value expression that evaluates to an address on a node naming `email` still resolves to the user who holds it, or fails the node pointing to `{ emailField }`. A node that does not name `email` still fails on an address no user holds.
+- **What a run records.** When a node's recipients mix users and such addresses, the node writes two `sys_notification` events: one for the users on the node's `channels`, which the node's `notificationId` output names, and one for the addresses on `email` alone. The `delivered`, `enqueued` and `failed` outputs add up both.
+- **Who moves.** Nobody needs to change a flow. A report or audit over `sys_inbox_message` no longer sees rows whose `user_id` is an address.
@@ -0,0 +1,182 @@
+// Copyright (c) 2026 ObjectStack. Licensed under the Apache-2.0 license.
+
+import { describe, it, expect } from 'vitest';
+import {
+    MessagingService,
+    NotificationTemplateStore,
+    createEmailChannel,
+    createInboxChannel,
+    INBOX_OBJECT,
+    NOTIFICATION_EVENT_OBJECT,
+} from '@objectstack/service-messaging';
+import { assertEngineFindOnePredicate, type EngineFindOneQueryInput } from '@objectstack/metadata-core';
+import { AutomationEngine } from '../engine.js';
+import { registerNotifyNode } from './notify-node.js';
+
+/**
+ * [#25990] On a node whose `channels` name `email` AND another channel, an
+ * address written out in `recipients` that no user holds is mailed as written
+ * (ruling 6386629237 letter B). The other channels deliver to a user: the inbox
+ * keys its row by the recipient as a user id. So the address goes to the email
+ * channel only, and the inbox writes no row for it; before, it wrote a
+ * `sys_inbox_message` row whose `user_id` was the address, which no inbox reads.
+ *
+ * The node still succeeds when the email delivery succeeds, and an address a
+ * user holds keeps reaching that user's inbox and is mailed as before.
+ *
+ * Wired through the REAL `MessagingService` (inline fan-out) and the REAL
+ * inbox and email channels, over a data engine that stores the directory and
+ * records every row the stack writes.
+ */
+
+function silentLogger(): any {
+    const l: any = { info: () => {}, warn: () => {}, error: () => {}, debug: () => {} };
+    l.child = () => l;
+    return l;
+}
+
+interface Row { [key: string]: unknown; id: string }
+
+/** A data engine holding the users, and recording every row the stack writes. */
+function dataEngine(users: Row[], opts: { failUserLookup?: boolean } = {}) {
+    const written: Array<{ object: string; row: Record<string, unknown> }> = [];
+    let seq = 0;
+    const tables: Record<string, Row[]> = { sys_user: users };
+    const engine = {
+        async insert(object: string, row: Record<string, unknown>) {
+            const stored = { ...row, id: row.id != null ? String(row.id) : `row_${++seq}` };
+            written.push({ object, row: stored });
+            return stored;
+        },
+        async find() { return []; },
+        async findOne(object: string, query?: EngineFindOneQueryInput) {
+            assertEngineFindOnePredicate(object, query);
+            const where = (query as { where?: Record<string, unknown> } | undefined)?.where ?? {};
+            if (opts.failUserLookup && object === 'sys_user' && 'email' in where) throw new Error('directory offline');
+            // Equality on plain fields only: a combinator or operator is refused, never read as a field name.
+            const hit = (tables[object] ?? []).find((r) => Object.entries(where).every(([k, v]) => {
+                if (k.startsWith('$') || (typeof v === 'object' && v !== null)) {
+                    throw new Error(`this double matches equality on plain fields only: ${JSON.stringify(where)}`);
+                }
+                return r[k] === v;
+            }));
+            return hit ? { ...hit } : undefined;
+        },
+    };
+    return { engine, written };
+}
+
+const EXEC = { id: 'usr_exec', email: 'exec@company.example' };
+
+/** The stack: messaging with the inbox and email channels, and the notify node over them. */
+function boot(opts: { failUserLookup?: boolean } = {}) {
+    const { engine: data, written } = dataEngine([EXEC], opts);
+    const getData = () => data as any;
+    const mailed: unknown[] = [];
+    const messaging = new MessagingService({ logger: silentLogger(), getData });
+    messaging.registerChannel(createInboxChannel({ getData }));
+    messaging.registerChannel(createEmailChannel({
+        getEmail: () => ({
+            async send(input) {
+                mailed.push(input.to);
+                return { id: `mail_${mailed.length}` };
+            },
+        }),
+        getData,
+        store: new NotificationTemplateStore({ getData: () => undefined }),
+    }));
+    const engine = new AutomationEngine(silentLogger());
+    registerNotifyNode(engine, {
+        logger: silentLogger(),
+        getService: (name: string) => (name === 'messaging' ? messaging : name === 'data' ? getData() : undefined),
+    } as any);
+    return { engine, written, mailed };
+}
+
+function notifyFlow(config: Record<string, unknown>): any {
+    return {
+        name: 'escalation',
+        label: 'Escalation',
+        type: 'autolaunched',
+        nodes: [
+            { id: 'start', type: 'start', label: 'Start' },
+            { id: 'alert_exec', type: 'notify', label: 'Alert Exec', config: { title: 'Critical', ...config } },
+            { id: 'end', type: 'end', label: 'End' },
+        ],
+        edges: [
+            { id: 'e1', source: 'start', target: 'alert_exec' },
+            { id: 'e2', source: 'alert_exec', target: 'end' },
+        ],
+    };
+}
+
+async function runOnce(stack: ReturnType<typeof boot>, config: Record<string, unknown>, record?: Record<string, unknown>) {
+    stack.engine.registerFlow('escalation', notifyFlow(config));
+    const context = record ? { tenantId: 'org_1', object: 'crm_lead', record } : { tenantId: 'org_1' };
+    const run = await stack.engine.execute('escalation', context as any);
+    const runs = await stack.engine.listRuns('escalation');
+    const step = runs[0]?.steps.find((s) => s.nodeId === 'alert_exec');
+    return { run, step };
+}
+
+const rowsOf = (stack: ReturnType<typeof boot>, object: string) =>
+    stack.written.filter((w) => w.object === object).map((w) => w.row);
+
+const BOTH = ['inbox', 'email'];
+
+describe('#25990 — a written-out address no user holds, on a node naming inbox and email', () => {
+    it.each([
+        ['bare', 'exec@example.com'],
+        ['as user:ADDRESS', 'user:exec@example.com'],
+        ['as user:ADDRESS of an address a user holds', 'user:exec@company.example'],
+    ])('is mailed as written and writes no inbox row (%s)', async (_label, recipient) => {
+        const stack = boot();
+        const { run } = await runOnce(stack, { recipients: [recipient], channels: BOTH });
+        expect(run.success).toBe(true);
+        expect(stack.mailed).toEqual([recipient.replace(/^user:/, '')]);
+        expect(rowsOf(stack, INBOX_OBJECT)).toEqual([]);
+        // The one recipient, and the one delivery a channel accepted: its mail.
+        expect(run.summary).toMatchObject({ selected: 1, acted: 1 });
+    });
+
+    it('beside a user, the user still gets the inbox row and the mail; the address only the mail', async () => {
+        const stack = boot();
+        const { run } = await runOnce(stack, { recipients: ['usr_exec', 'stranger@example.com'], channels: BOTH });
+        expect(run.success).toBe(true);
+        expect(rowsOf(stack, INBOX_OBJECT).map((r) => r.user_id)).toEqual(['usr_exec']);
+        expect([...stack.mailed].sort()).toEqual(['exec@company.example', 'stranger@example.com']);
+        // Both recipients are counted, and every delivery a channel accepted:
+        // the user's inbox row and mail, and the address's mail.
+        expect(run.summary).toMatchObject({ selected: 2, acted: 3 });
+        // The address's mail is its own notification, on the email channel alone.
+        expect(rowsOf(stack, NOTIFICATION_EVENT_OBJECT)).toHaveLength(2);
+    });
+
+    it('a written-out address a user holds keeps reaching that user\'s inbox and is mailed, as before', async () => {
+        const stack = boot();
+        const { run } = await runOnce(stack, { recipients: ['exec@company.example'], channels: BOTH });
+        expect(run.success).toBe(true);
+        expect(rowsOf(stack, INBOX_OBJECT).map((r) => r.user_id)).toEqual(['usr_exec']);
+        expect(stack.mailed).toEqual(['exec@company.example']);
+    });
+
+    it('when the directory cannot say who holds it, the address is still mailed and never keys an inbox row', async () => {
+        const stack = boot({ failUserLookup: true });
+        const { run } = await runOnce(stack, { recipients: ['exec@example.com'], channels: BOTH });
+        expect(run.success).toBe(true);
+        expect(stack.mailed).toEqual(['exec@example.com']);
+        expect(rowsOf(stack, INBOX_OBJECT)).toEqual([]);
+    });
+
+    it('a computed address a user holds reaches that user\'s inbox on a both-channels node', async () => {
+        const stack = boot();
+        const { run } = await runOnce(
+            stack,
+            { recipients: { dialect: 'cel', source: 'record.owner_email' }, channels: BOTH },
+            { id: 'lead_1', owner_email: 'exec@company.example' },
+        );
+        expect(run.success).toBe(true);
+        expect(rowsOf(stack, INBOX_OBJECT).map((r) => r.user_id)).toEqual(['usr_exec']);
+        expect(stack.mailed).toEqual(['exec@company.example']);
+    });
+});