diff --git a/services/api/src/services/admin/activity-repository.drizzle.ts b/services/api/src/services/admin/activity-repository.drizzle.ts
index c600b0d9..5d1cef07 100644
--- a/services/api/src/services/admin/activity-repository.drizzle.ts
+++ b/services/api/src/services/admin/activity-repository.drizzle.ts
@@ -55,6 +55,7 @@ interface ActivityRowSelect {
   id: string
   ts: Date
   who: string | null
+  actorless: boolean
   where_label: string | null
   action: string | null
   event_type: string | null
@@ -67,6 +68,7 @@ function toRecord(r: ActivityRowSelect): ActivitySourceRecord {
     id: r.id,
     ts: r.ts,
     who: r.who ?? "",
+    actorless: r.actorless,
     where: r.where_label ?? "",
     action: r.action,
     eventType: r.event_type,
@@ -147,7 +149,7 @@ export function makeDrizzleActivityRepository(sql: Sql): ActivityRepository {
       if (wants("audit")) {
         branches.push(sql`(
           SELECT 'audit'::text AS source, a.id::text AS id, a.created_at AS ts,
-                 u.display_name AS who, a.target AS where_label,
+                 u.display_name AS who, a.actor_id IS NULL AS actorless, a.target AS where_label,
                  a.action AS action, NULL::text AS event_type, a.target AS subject
           FROM audit_log a
           LEFT JOIN users u ON u.id = a.actor_id
@@ -164,7 +166,7 @@ export function makeDrizzleActivityRepository(sql: Sql): ActivityRepository {
       if (wants("report")) {
         branches.push(sql`(
           SELECT 'report'::text AS source, r.id::text AS id, r.created_at AS ts,
-                 ru.display_name AS who, j.name AS where_label,
+                 ru.display_name AS who, false AS actorless, j.name AS where_label,
                  NULL::text AS action, NULL::text AS event_type, r.category AS subject
           FROM reports r
           LEFT JOIN users ru ON ru.id = r.reporter_user_id
@@ -180,7 +182,7 @@ export function makeDrizzleActivityRepository(sql: Sql): ActivityRepository {
       if (wants("cleanup")) {
         branches.push(sql`(
           SELECT 'cleanup'::text AS source, c.id::text AS id, c.created_at AS ts,
-                 cu.display_name AS who, c.address AS where_label,
+                 cu.display_name AS who, false AS actorless, c.address AS where_label,
                  NULL::text AS action, NULL::text AS event_type, c.title AS subject
           FROM cleanups c
           LEFT JOIN users cu ON cu.id = c.organizer_user_id
@@ -195,7 +197,7 @@ export function makeDrizzleActivityRepository(sql: Sql): ActivityRepository {
       if (wants("mail_event")) {
         branches.push(sql`(
           SELECT 'mail_event'::text AS source, e.id::text AS id, e.created_at AS ts,
-                 t.org AS who, COALESCE(t.org, t.jurisdiction_geoid) AS where_label,
+                 t.org AS who, false AS actorless, COALESCE(t.org, t.jurisdiction_geoid) AS where_label,
                  NULL::text AS action, e.type AS event_type, t.subject AS subject
           FROM mail_events e
           LEFT JOIN mail_threads t ON t.id = e.thread_id
diff --git a/services/api/src/services/admin/activity-service.ts b/services/api/src/services/admin/activity-service.ts
index f28cbefb..5f70959e 100644
--- a/services/api/src/services/admin/activity-service.ts
+++ b/services/api/src/services/admin/activity-service.ts
@@ -20,6 +20,7 @@ export interface ActivitySourceRecord {
   id: string
   ts: Date
   who: string
+  actorless?: boolean
   where: string
   action?: string | null
   eventType?: string | null
@@ -220,6 +221,13 @@ export function describeAuditAction(action: string): string {
   return map[action] ?? action
 }
 
+const PUBLIC_AUDIT_ACTIONS: ReadonlySet<string> = new Set(["discovery.contact_suggested"])
+
+function auditActor(record: ActivitySourceRecord, action: string): string {
+  if (record.actorless !== true) return record.who || "Operator"
+  return PUBLIC_AUDIT_ACTIONS.has(action) ? "A neighbor" : "System"
+}
+
 export function classifyActivity(record: ActivitySourceRecord, ref: Date): ActivityItemDTO {
   const ts = relativeAgo(record.ts, ref)
   if (record.source === "report") {
@@ -245,7 +253,7 @@ export function classifyActivity(record: ActivitySourceRecord, ref: Date): Activ
   }
   const action = record.action ?? ""
   const kind = classifyAuditAction(action)
-  return item(kind, record.who || "Operator", describeAuditAction(action), record.where, ts)
+  return item(kind, auditActor(record, action), describeAuditAction(action), record.where, ts)
 }
 
 function item(
diff --git a/services/api/test/integration/admin-activity.test.ts b/services/api/test/integration/admin-activity.test.ts
index 59c226c8..2fef075b 100644
--- a/services/api/test/integration/admin-activity.test.ts
+++ b/services/api/test/integration/admin-activity.test.ts
@@ -104,6 +104,7 @@ describe.skipIf(!pg)("admin activity repository (integration: real schema)", ()
     // The audit row carries the actor name + action.
     const audit = records.find((r) => r.source === "audit")!
     expect(audit.who).toBe("Operator")
+    expect(audit.actorless).toBe(false)
     expect(audit.action).toBe("gov_claim.approved")
     // The report carries the category subject + the jurisdiction place.
     const report = records.find((r) => r.source === "report")!
@@ -115,6 +116,20 @@ describe.skipIf(!pg)("admin activity repository (integration: real schema)", ()
     expect(mail.eventType).toBe("bounced")
   })
 
+  it("marks only an audit row with no actor as actorless", async () => {
+    await seedOneOfEachSource()
+    await h.sql`
+      INSERT INTO audit_log (actor_id, action, target)
+      VALUES (NULL, 'mail.reply_published_without_text', 'mail:1')
+    `
+
+    const { records } = await repo.list(listArgs())
+    expect(records).toHaveLength(5)
+    expect(records.filter((r) => r.actorless).map((r) => r.action)).toEqual([
+      "mail.reply_published_without_text",
+    ])
+  })
+
   it("sort=oldest walks the same merged feed the other way", async () => {
     await seedOneOfEachSource()
 
diff --git a/services/api/test/unit/admin-activity.test.ts b/services/api/test/unit/admin-activity.test.ts
index 19552c9e..53391598 100644
--- a/services/api/test/unit/admin-activity.test.ts
+++ b/services/api/test/unit/admin-activity.test.ts
@@ -143,6 +143,19 @@ describe("classifyActivity (per source)", () => {
         .who,
     ).toBe("Operator")
   })
+
+  it("labels an audit row with no actor as the system, or a neighbor for a public suggestion", () => {
+    const who = (action: string, actorless = true) =>
+      classifyActivity(
+        { source: "audit", id: "a", ts: NOW, who: "", actorless, where: "", action },
+        NOW,
+      ).who
+    expect(who("mail.reply_published_without_text")).toBe("System")
+    expect(who("mail.send_failed")).toBe("System")
+    expect(who("report.routed")).toBe("System")
+    expect(who("discovery.contact_suggested")).toBe("A neighbor")
+    expect(who("mail.sent", false)).toBe("Operator")
+  })
 })
 
 describe("activity service wiring", () => {