diff --git a/client/src/telethon/_impl/client/client/client.py b/client/src/telethon/_impl/client/client/client.py
index 8fec6a95..91564209 100644
--- a/client/src/telethon/_impl/client/client/client.py
+++ b/client/src/telethon/_impl/client/client/client.py
@@ -10,6 +10,7 @@ from typing_extensions import Self
 
 from ....version import __version__ as default_version
 from ...mtsender import Connector, Sender
+from ...mtsender.reconnection import NoReconnect, ReconnectionPolicy
 from ...session import (
     ChannelRef,
     ChatHashCache,
@@ -215,6 +216,7 @@ class Client:
         lang_code: Optional[str] = None,
         datacenter: Optional[DataCenter] = None,
         connector: Optional[Connector] = None,
+        reconnection_policy: Optional[ReconnectionPolicy] = None,
     ) -> None:
         assert __package__
         base_logger = logger or logging.getLogger(__package__[: __package__.index(".")])
@@ -246,7 +248,7 @@ class Client:
             update_queue_limit=update_queue_limit,
             base_logger=base_logger,
             connector=connector or (lambda ip, port: asyncio.open_connection(ip, port)),
-            reconnection_policy=None,
+            reconnection_policy=reconnection_policy or NoReconnect(),
         )
 
         self._session = Session()
diff --git a/client/src/telethon/_impl/client/client/net.py b/client/src/telethon/_impl/client/client/net.py
index 2770ed9a..e790457d 100644
--- a/client/src/telethon/_impl/client/client/net.py
+++ b/client/src/telethon/_impl/client/client/net.py
@@ -46,6 +46,7 @@ class Config:
     api_hash: str
     base_logger: logging.Logger
     connector: Connector
+    reconnection_policy: ReconnectionPolicy
     device_model: str = field(default_factory=default_device_model)
     system_version: str = field(default_factory=default_system_version)
     app_version: str = __version__
@@ -55,7 +56,6 @@ class Config:
     datacenter: Optional[DataCenter] = None
     flood_sleep_threshold: int = 60
     update_queue_limit: Optional[int] = None
-    reconnection_policy: Optional[ReconnectionPolicy] = None
 
 
 KNOWN_DCS = [
diff --git a/client/src/telethon/_impl/mtsender/errors.py b/client/src/telethon/_impl/mtsender/errors.py
index 227d6fdd..26c94f06 100644
--- a/client/src/telethon/_impl/mtsender/errors.py
+++ b/client/src/telethon/_impl/mtsender/errors.py
@@ -1,11 +1,6 @@
-import io
+from struct import error as struct_error
 
 from ..mtproto.mtp.types import DeserializationError
 from ..mtproto.transport.abcs import TransportError
 
-ReadError = io.BlockingIOError | TransportError | DeserializationError
-
-
-class IOError(io.BlockingIOError):
-    def __init__(self, *args: object) -> None:
-        super().__init__(*args)
+ReadError = struct_error | TransportError | DeserializationError
diff --git a/client/src/telethon/_impl/mtsender/sender.py b/client/src/telethon/_impl/mtsender/sender.py
index f13f52b8..f9b8c1f5 100644
--- a/client/src/telethon/_impl/mtsender/sender.py
+++ b/client/src/telethon/_impl/mtsender/sender.py
@@ -29,7 +29,7 @@ from ..tl import Request as RemoteCall
 from ..tl.abcs import Updates
 from ..tl.core import Serializable
 from ..tl.mtproto.functions import ping_delay_disconnect
-from ..tl.types import UpdateDeleteMessages, UpdateShort
+from ..tl.types import UpdateDeleteMessages, UpdateShort, UpdatesTooLong
 from ..tl.types.messages import AffectedFoundMessages, AffectedHistory, AffectedMessages
 from .reconnection import ReconnectionPolicy
 
@@ -165,7 +165,7 @@ class Sender:
     dc_id: int
     addr: str
     _connector: Connector
-    _reconnection_policy: Optional[ReconnectionPolicy]
+    _reconnection_policy: ReconnectionPolicy
     _logger: logging.Logger
     _reader: AsyncReader
     _writer: AsyncWriter
@@ -190,7 +190,7 @@ class Sender:
         addr: str,
         *,
         connector: Connector,
-        reconnection_policy: Optional[ReconnectionPolicy],
+        reconnection_policy: ReconnectionPolicy,
         base_logger: logging.Logger,
     ) -> Self:
         ip, port = addr.split(":")
@@ -249,7 +249,7 @@ class Sender:
         try:
             await self._step()
         except Exception as error:
-            self._on_error(error)
+            await self._on_error(error)
 
     async def _step(self) -> None:
         if not self._writing:
@@ -308,10 +308,7 @@ class Sender:
                 self._logger.warning(f"auto-reconnect failed {attempts} time(s): {e!r}")
                 await asyncio.sleep(1)
 
-                delay = False
-
-                if self._reconnection_policy is not None:
-                    delay = self._reconnection_policy.should_retry(attempts)
+                delay = self._reconnection_policy.should_retry(attempts)
 
                 if delay:
                     if delay is not True:
@@ -379,7 +376,7 @@ class Sender:
             if isinstance(req.state, Serialized):
                 req.state = Sent(req.state.msg_id, req.state.container_msg_id)
 
-    def _on_error(self, error: Exception):
+    async def _on_error(self, error: Exception) -> None:
         self._logger.info(f"handling error: {error}")
         self._transport.reset()
         self._mtp.reset()
@@ -392,10 +389,17 @@ class Sender:
         self._read_buffer.clear()
         self._mtp_buffer.clear()
 
-        match error:
-            # TODO
-            case DeserializationFailure():
-                pass
+        if isinstance(error, struct.error) and self._reconnection_policy.should_retry(
+            0
+        ):
+            self._logger.info(f"read error occurred: {error}")
+            await self._try_connect()
+
+            for req in self._requests:
+                req.state = NotSerialized()
+
+            self._updates.append(UpdatesTooLong())
+            return
 
         self._logger.warning(
             f"marking all {len(self._requests)} request(s) as failed: {error}"
@@ -561,7 +565,7 @@ async def connect(
     auth_key: Optional[bytes],
     base_logger: logging.Logger,
     connector: Connector,
-    reconnection_policy: Optional[ReconnectionPolicy] = None,
+    reconnection_policy: ReconnectionPolicy,
 ) -> Sender:
     if auth_key is None:
         sender = await Sender.connect(