diff --git a/gateway/relay/adapter.py b/gateway/relay/adapter.py
index 6f2a806008..ade3c0b4c7 100644
--- a/gateway/relay/adapter.py
+++ b/gateway/relay/adapter.py
@@ -109,6 +109,10 @@ def _profile_from_session_key(session_key: str) -> Optional[str]:
 class RelayAdapter(BasePlatformAdapter):
     """Generic relay adapter advertising a connector-negotiated capability profile."""
 
+    # Connector egress splits against negotiated max_message_length, so the
+    # gateway-level cap must not pre-truncate relay deliveries.
+    splits_long_messages = True
+
     def __init__(
         self,
         config: PlatformConfig,
diff --git a/tests/gateway/test_delivery.py b/tests/gateway/test_delivery.py
index c8991fd5d1..4334007e7f 100644
--- a/tests/gateway/test_delivery.py
+++ b/tests/gateway/test_delivery.py
@@ -64,8 +64,8 @@ class TestPlatformNameCaseInsensitivity:
 class _RelayDeliveryTransport:
     """Relay transport that advertises Slack and records outbound wire frames."""
 
-    def __init__(self):
-        self._identities = [("slack", "bot-1")]
+    def __init__(self, platform="slack"):
+        self._identities = [(platform, "bot-1")]
         self.sent = []
 
     async def send_outbound(self, action, *, platform=None):
@@ -75,18 +75,18 @@ class _RelayDeliveryTransport:
         return {"success": True, "message_id": "relay-message-1"}
 
 
-def _make_relay(transport):
+def _make_relay(transport, platform="slack", max_message_length=4000):
     return RelayAdapter(
         PlatformConfig(enabled=True),
         CapabilityDescriptor(
             contract_version=CONTRACT_VERSION,
-            platform="slack",
-            label="Slack",
-            max_message_length=4000,
+            platform=platform,
+            label=platform.capitalize(),
+            max_message_length=max_message_length,
             supports_draft_streaming=False,
             supports_edit=True,
             supports_threads=True,
-            markdown_dialect="slack",
+            markdown_dialect=platform,
             len_unit="chars",
         ),
         transport=cast(Any, transport),
@@ -94,8 +94,9 @@ def _make_relay(transport):
 
 
 @pytest.mark.asyncio
-async def test_relay_fronted_target_delivers_without_prior_inbound_chat_state(tmp_path, monkeypatch):
-    """A persisted Slack home must work immediately after a gateway restart."""
+@pytest.mark.parametrize("content", ["scheduled result", "x" * 5000], ids=["short", "oversized"])
+async def test_relay_fronted_target_delivers_without_prior_inbound_chat_state(tmp_path, monkeypatch, content):
+    """A persisted Slack home receives the complete payload from the gateway."""
     monkeypatch.setattr("gateway.delivery.get_hermes_home", lambda: tmp_path)
     transport = _RelayDeliveryTransport()
     relay = _make_relay(transport)
@@ -117,16 +118,23 @@ async def test_relay_fronted_target_delivers_without_prior_inbound_chat_state(tm
 
     result = await router._deliver_to_platform(
         DeliveryTarget(platform=Platform.SLACK, chat_id="D123"),
-        "scheduled result",
+        content,
         metadata={"job_id": "cron-1", "user_id": "stale-user"},
     )
 
     assert getattr(result, "success", False) is True
-    assert len(transport.sent) == 1
+    assert transport.sent
     action, wire_platform = transport.sent[0]
     assert wire_platform == "slack"
     assert action["chat_id"] == "D123"
     assert action["metadata"] == {"job_id": "cron-1", "user_id": "U123"}
+    assert action["content"] == content
+    saved_files = list(tmp_path.glob("cron/output/cron-1_*.txt"))
+    if len(content) > 4000:
+        assert len(saved_files) == 1
+        assert saved_files[0].read_text(encoding="utf-8") == content
+    else:
+        assert saved_files == []
 
 
 class RecordingAdapter:
@@ -402,3 +410,46 @@ def test_local_delivery_writes_non_ascii_on_windows_codepage(tmp_path, monkeypat
     written = Path(result["path"]).read_text(encoding="utf-8")
     assert "完了 ✅ café" in written
     assert "日次レポート" in written
+
+
+@pytest.mark.asyncio
+async def test_relay_fronted_telegram_target_receives_payload_above_its_own_limit(tmp_path, monkeypatch):
+    """The gateway does not pre-truncate for a relay-fronted Telegram chat.
+
+    The connector splits egress against the negotiated max_message_length
+    (4096 for Telegram), so the full payload must reach the transport intact.
+    """
+    monkeypatch.setattr("gateway.delivery.get_hermes_home", lambda: tmp_path)
+    transport = _RelayDeliveryTransport(platform="telegram")
+    relay = _make_relay(transport, platform="telegram", max_message_length=4096)
+    config = GatewayConfig(
+        platforms={
+            Platform.RELAY: PlatformConfig(enabled=True),
+            Platform.TELEGRAM: PlatformConfig(
+                enabled=False,
+                home_channel=HomeChannel(
+                    platform=Platform.TELEGRAM,
+                    chat_id="12345",
+                    name="Owner",
+                    user_id="777",
+                ),
+            ),
+        },
+    )
+    router = DeliveryRouter(config, adapters={Platform.RELAY: relay})
+    content = "y" * 30_000
+
+    result = await router._deliver_to_platform(
+        DeliveryTarget(platform=Platform.TELEGRAM, chat_id="12345"),
+        content,
+        metadata={"job_id": "cron-2", "user_id": "stale-user"},
+    )
+
+    assert getattr(result, "success", False) is True
+    action, wire_platform = transport.sent[0]
+    assert wire_platform == "telegram"
+    assert action["content"] == content
+    assert len(action["content"]) > 4096
+    saved_files = list(tmp_path.glob("cron/output/cron-2_*.txt"))
+    assert len(saved_files) == 1
+    assert saved_files[0].read_text(encoding="utf-8") == content