human hand off fix

backend/app/services/human_handoff_service.py

@@ -25,7 +25,6 @@ from app.services.handoff_delivery import (
 from app.services.handoff_email_templates import (
     attach_quoted_history,
     build_gmail_quote,
-    format_sender_line,
     sender_display_name,
 )
 from app.services.handoff_evaluator import evaluate_handoff
@@ -206,16 +205,18 @@ async def _latest_thread_message(
     account_id: str,
     thread_id: ObjectId,
     scope: str,
+    exclude_message_ids: list | None = None,
 ) -> dict | None:
-    pipeline = [
-        {
-            "$match": {
+    match = {
         "account_id": account_id,
         "thread_id": thread_id,
         "message_scope": scope,
         "deletion_state": {"$in": [None, ""]},
     }
-        },
+    if exclude_message_ids:
+        match["message_id"] = {"$nin": list(exclude_message_ids)}
+    pipeline = [
+        {"$match": match},
         {"$sort": {"event_at": -1, "_id": -1}},
         {"$limit": 1},
         {
@@ -720,18 +721,66 @@ async def process_human_reply(
     return human_message
 
 
-def _mirror_from_identity(source: dict, agent_name: str) -> str:
+def _mirror_from_identity(
+    source: dict, agent_name: str, agent_email: str
+) -> tuple[str, str]:
     if source.get("direction") == "inbound":
-        return format_sender_line(source.get("sender") or {})
-    return agent_name
+        sender = source.get("sender") or {}
+        address = (sender.get("address") or "").strip()
+        return sender_display_name(sender), address or agent_email
+    return agent_name, agent_email
 
 
-def _mirror_body(source: dict, payload) -> tuple[str, str | None]:
-    new_text = (source.get("new_reply_content") or "").strip()
-    new_html = (source.get("new_reply_html") or "").strip() or None
-    if new_text:
-        return new_text, new_html
-    return payload.body_text, payload.body_html
+def _body_has_quote_trail(body_text: str | None, body_html: str | None) -> bool:
+    html = body_html or ""
+    text = body_text or ""
+    if re.search(r"gmail_quote|blockquote", html, re.IGNORECASE):
+        return True
+    if re.search(r"(?m)^>+", text):
+        return True
+    if re.search(r"wrote:\s*$", text, re.IGNORECASE | re.MULTILINE):
+        return True
+    return "-----Original Message-----" in text
+
+
+async def _mirror_body_with_trail(
+    database,
+    *,
+    account_id: str,
+    handoff: dict,
+    source: dict,
+    payload,
+) -> tuple[str, str | None]:
+    text = payload.body_text or ""
+    html = payload.body_html
+    if _body_has_quote_trail(text, html):
+        return text, html or None
+    parent = await _latest_thread_message(
+        database,
+        account_id=account_id,
+        thread_id=handoff["external_thread_id"],
+        scope=MESSAGE_SCOPE_EXTERNAL,
+        exclude_message_ids=[source["_id"]],
+    )
+    if parent is None:
+        return text, html
+    parent_payload = await load_mirror_payload(parent)
+    quoted_text, quoted_html = build_gmail_quote(
+        sender=parent.get("sender") or {},
+        event_at=(
+            parent.get("sent_at")
+            or parent.get("received_at")
+            or parent.get("created_at")
+        ),
+        body_text=parent_payload.body_text or parent.get("body_text") or "",
+        body_html=parent_payload.body_html or parent.get("body_html"),
+    )
+    return attach_quoted_history(
+        new_text=(source.get("new_reply_content") or text).strip() or text,
+        new_html=source.get("new_reply_html") or html,
+        quoted_text=quoted_text,
+        quoted_html=quoted_html,
+    )
 
 
 async def _deliver_mirror(database, job: dict, handoff: dict, source: dict) -> ObjectId:
@@ -748,8 +797,16 @@ async def _deliver_mirror(database, job: dict, handoff: dict, source: dict) -> O
         job["account_id"], handoff["agent_email"]
     )
     payload = await load_mirror_payload(source)
-    body_text, body_html = _mirror_body(source, payload)
-    from_name = _mirror_from_identity(source, sender_name)
+    body_text, body_html = await _mirror_body_with_trail(
+        database,
+        account_id=job["account_id"],
+        handoff=handoff,
+        source=source,
+        payload=payload,
+    )
+    from_name, from_address = _mirror_from_identity(
+        source, sender_name, handoff["agent_email"]
+    )
     parent = await _latest_thread_message(
         database,
         account_id=job["account_id"],
@@ -761,7 +818,7 @@ async def _deliver_mirror(database, job: dict, handoff: dict, source: dict) -> O
     if parent and not re.match(r"^re:\s*", subject, re.IGNORECASE):
         subject = f"Re: {subject}"
     internet_message_id = await deliver_email(
-        sender=handoff["agent_email"],
+        sender=from_address,
         sender_name=from_name,
         recipients=[handoff["human_email"]],
         cc=[],
@@ -770,6 +827,8 @@ async def _deliver_mirror(database, job: dict, handoff: dict, source: dict) -> O
         body_text=body_text,
         body_html=body_html,
         domain=domain,
+        reply_to=handoff["agent_email"],
+        envelope_sender=handoff["agent_email"],
         in_reply_to=threading.get("in_reply_to"),
         references=threading.get("references"),
         message_id=job["generated_message_id"],
@@ -784,7 +843,7 @@ async def _deliver_mirror(database, job: dict, handoff: dict, source: dict) -> O
         account_id=job["account_id"],
         thread_id=handoff["handoff_thread_id"],
         direction="outbound",
-        sender={"name": from_name, "address": handoff["agent_email"]},
+        sender={"name": from_name, "address": from_address},
         recipients=[
             {
                 "name": handoff.get("human_name", ""),

backend/app/services/mail_sender.py

@@ -237,6 +237,7 @@ async def deliver_email(
     message_id: str | None = None,
     inline_parts: list[ExtractedMimePart] | None = None,
     file_attachments: list[ExtractedMimePart] | None = None,
+    envelope_sender: str | None = None,
 ) -> str:
     _, sender_address = _sender_identity(sender, sender_name)
     message = build_message(
@@ -259,7 +260,7 @@ async def deliver_email(
     log_signed_mime_headers(signed)
     await send_via_smtp(
         signed,
-        sender=sender_address,
+        sender=envelope_sender or sender_address,
         recipients=[*recipients, *cc, *bcc],
     )
     return str(message["Message-ID"])

backend/tests/test_human_handoff_service.py

@@ -1,6 +1,10 @@
+import pytest
+
 from app.services.human_handoff_service import (
     MESSAGE_SCOPE_EXTERNAL,
     MESSAGE_SCOPE_HANDOFF,
+    _body_has_quote_trail,
+    _mirror_from_identity,
     build_handoff_subject,
     maybe_trigger_handoff,
     process_human_reply,
@@ -20,6 +24,80 @@ def test_human_handoff_runtime_is_enabled():
     assert callable(resolve_handoff_from_inbound)
 
 
+@pytest.mark.asyncio
+async def test_mirror_body_appends_external_history_when_missing(monkeypatch):
+    from types import SimpleNamespace
+    from unittest.mock import AsyncMock
+
+    from app.services.human_handoff_service import _mirror_body_with_trail
+
+    parent = {
+        "_id": "parent",
+        "sender": {"name": "Parth Dixit", "address": "parthdixit091@gmail.com"},
+        "body_text": "sender: C\n\nOn earlier Suyash Dixit wrote:\n> responder: B",
+        "body_html": None,
+        "sent_at": None,
+    }
+    monkeypatch.setattr(
+        "app.services.human_handoff_service._latest_thread_message",
+        AsyncMock(return_value=parent),
+    )
+    monkeypatch.setattr(
+        "app.services.human_handoff_service.load_mirror_payload",
+        AsyncMock(return_value=SimpleNamespace(body_text=parent["body_text"], body_html=None)),
+    )
+    text, html = await _mirror_body_with_trail(
+        SimpleNamespace(),
+        account_id="account-1",
+        handoff={"external_thread_id": "thread"},
+        source={"_id": "child", "new_reply_content": "responder: D", "new_reply_html": None},
+        payload=SimpleNamespace(body_text="responder: D", body_html=None),
+    )
+    assert text.startswith("responder: D")
+    assert "parthdixit091@gmail.com" in text
+    assert "> sender: C" in text
+    assert "responder: B" in text
+    assert html and "gmail_quote" in html
+
+
+def test_quote_trail_is_detected_in_forwarded_history():
+    assert _body_has_quote_trail(
+        "responder: B\n\nOn Tue, Oct 6, 2026 at 7:44 AM Suyash Dixit wrote:\n> sender: A",
+        None,
+    )
+    assert _body_has_quote_trail(
+        "sender: C",
+        '<div>sender: C</div><div class="gmail_quote">sender: A</div>',
+    )
+    assert _body_has_quote_trail("sender: E", None) is False
+
+
+def test_mirror_from_uses_one_address_not_both():
+    name, address = _mirror_from_identity(
+        {
+            "direction": "inbound",
+            "sender": {
+                "name": "Suyash Dixit",
+                "address": "suyashdixit091@gmail.com",
+            },
+        },
+        "Suyash Dixit",
+        "suyash@gentic.email",
+    )
+    assert name == "Suyash Dixit"
+    assert address == "suyashdixit091@gmail.com"
+    assert "gentic.email" not in address
+
+    agent_name, agent_address = _mirror_from_identity(
+        {"direction": "outbound", "sender": {"address": "suyash@gentic.email"}},
+        "Suyash Dixit",
+        "suyash@gentic.email",
+    )
+    assert agent_name == "Suyash Dixit"
+    assert agent_address == "suyash@gentic.email"
+    assert "gmail.com" not in agent_address
+
+
 def test_private_subject_contains_customer_name_and_external_subject():
     subject = build_handoff_subject(
         sender_name="Parth Dixit",