diff --git a/meshai/config.py b/meshai/config.py
index 7faaf7e..ca028ee 100644
--- a/meshai/config.py
+++ b/meshai/config.py
@@ -35,8 +35,8 @@ class ConnectionConfig:
 class ResponseConfig:
     """Response behavior settings."""
 
-    delay_min: float = 3.0
-    delay_max: float = 5.0
+    delay_min: float = 1.5
+    delay_max: float = 2.5
     max_length: int = 200
     max_messages: int = 3
 
diff --git a/meshai/responder.py b/meshai/responder.py
index ea63c6b..6699816 100644
--- a/meshai/responder.py
+++ b/meshai/responder.py
@@ -1,85 +1,93 @@
-"""Response handling - delays and message delivery."""
-
-import asyncio
-import logging
-import random
-from typing import Optional
-
-from .config import ResponseConfig
-from .connector import MeshConnector
-
-logger = logging.getLogger(__name__)
-
-
-class Responder:
-    """Handles response delivery with pacing."""
-
-    def __init__(self, config: ResponseConfig, connector: MeshConnector):
-        self.config = config
-        self.connector = connector
-
-    async def send_response(
-        self,
-        messages: list[str] | str,
-        destination: Optional[str] = None,
-        channel: int = 0,
-    ) -> bool:
-        """Send response messages with ACK waiting and retry.
-
-        For DMs: waits for ACK before sending next message, retries once on failure.
-        For broadcasts: uses delay-based pacing (no ACK for broadcasts).
-        """
-        if isinstance(messages, str):
-            messages = [messages]
-
-        if not messages:
-            return True
-
-        success = True
-        is_dm = destination is not None
-
-        for i, msg in enumerate(messages):
-            # Randomized delay before sending (except first message)
-            if i > 0:
-                delay = random.uniform(self.config.delay_min, self.config.delay_max)
-                await asyncio.sleep(delay)
-
-            if is_dm and hasattr(self.connector, 'send_and_wait_ack'):
-                # DMs: send and wait for ACK
-                ack = await asyncio.get_event_loop().run_in_executor(
-                    None,
-                    self.connector.send_and_wait_ack,
-                    msg, destination, channel, 30.0,
-                )
-
-                if not ack:
-                    # Retry once
-                    logger.warning(f"No ACK for msg {i+1}/{len(messages)}, retrying...")
-                    await asyncio.sleep(random.uniform(3.0, 5.0))
-                    ack = await asyncio.get_event_loop().run_in_executor(
-                        None,
-                        self.connector.send_and_wait_ack,
-                        msg, destination, channel, 30.0,
-                    )
-                    if not ack:
-                        logger.error(f"No ACK after retry for msg {i+1}/{len(messages)}, skipping remaining")
-                        success = False
-                        break
-
-                logger.debug(f"Sent+ACK msg {i+1}/{len(messages)}: {msg[:50]}...")
-            else:
-                # Broadcasts or fallback: fire and delay
-                sent = self.connector.send_message(
-                    text=msg,
-                    destination=destination,
-                    channel=channel,
-                )
-                if not sent:
-                    logger.error(f"Failed to send message {i+1}/{len(messages)}")
-                    success = False
-                    break
-
-                logger.debug(f"Sent msg {i+1}/{len(messages)}: {msg[:50]}...")
-
-        return success
-
+"""Response handling - delays and message delivery."""
+
+import asyncio
+import logging
+import random
+from typing import Optional
+
+from .config import ResponseConfig
+from .connector import MeshConnector
+
+logger = logging.getLogger(__name__)
+
+
+class Responder:
+    """Handles response delivery with pacing."""
+
+    def __init__(self, config: ResponseConfig, connector: MeshConnector):
+        self.config = config
+        self.connector = connector
+
+    async def send_response(
+        self,
+        messages: list[str] | str,
+        destination: Optional[str] = None,
+        channel: int = 0,
+    ) -> bool:
+        """Send response messages with ACK-accelerated delivery.
+
+        DMs: Send -> wait for ACK -> if ACK, send next immediately.
+             If no ACK, retry once -> if still no ACK, abort.
+        Broadcasts: delay-based pacing (no ACK available).
+        """
+        if isinstance(messages, str):
+            messages = [messages]
+
+        if not messages:
+            return True
+
+        success = True
+        is_dm = destination is not None
+
+        for i, msg in enumerate(messages):
+            if is_dm and hasattr(self.connector, 'send_and_wait_ack'):
+                # Send and wait for ACK
+                ack = await asyncio.get_event_loop().run_in_executor(
+                    None,
+                    self.connector.send_and_wait_ack,
+                    msg, destination, channel, 30.0,
+                )
+
+                if ack:
+                    # ACK received - next message sends immediately (no delay)
+                    logger.debug(f"ACK msg {i+1}/{len(messages)}: {msg[:50]}...")
+                    continue
+
+                # No ACK - retry same message once after short pause
+                logger.warning(f"No ACK for msg {i+1}/{len(messages)}, retrying...")
+                await asyncio.sleep(2.0)
+
+                ack = await asyncio.get_event_loop().run_in_executor(
+                    None,
+                    self.connector.send_and_wait_ack,
+                    msg, destination, channel, 30.0,
+                )
+
+                if ack:
+                    logger.debug(f"ACK on retry msg {i+1}/{len(messages)}")
+                    continue
+
+                # Double failure - abort
+                logger.error(f"No ACK after retry msg {i+1}/{len(messages)}, aborting remaining")
+                success = False
+                break
+
+            else:
+                # Broadcasts or fallback: delay-based pacing
+                if i > 0:
+                    delay = random.uniform(self.config.delay_min, self.config.delay_max)
+                    await asyncio.sleep(delay)
+
+                sent = self.connector.send_message(
+                    text=msg,
+                    destination=destination,
+                    channel=channel,
+                )
+                if not sent:
+                    logger.error(f"Failed to send message {i+1}/{len(messages)}")
+                    success = False
+                    break
+
+                logger.debug(f"Sent msg {i+1}/{len(messages)}: {msg[:50]}...")
+
+        return success