diff --git a/src/v5/client.rs b/src/v5/client.rs
index d41ee6d8..5e7bf748 100644
--- a/src/v5/client.rs
+++ b/src/v5/client.rs
@@ -1,6 +1,6 @@
 use std::task::{Context, Poll};
 use std::time::Duration;
-use std::{fmt, io, marker::PhantomData, pin::Pin, rc::Rc};
+use std::{fmt, io, marker::PhantomData, num::NonZeroU16, pin::Pin, rc::Rc};
 
 use bytes::Bytes;
 use bytestring::ByteString;
@@ -11,7 +11,7 @@ use ntex::channel::mpsc;
 use ntex::service::{boxed, IntoService, IntoServiceFactory, Service, ServiceFactory};
 use ntex_codec::{AsyncRead, AsyncWrite};
 
-use crate::error::{DecodeError, EncodeError, MqttError};
+use crate::error::{DecodeError, EncodeError, MqttError, ProtocolError};
 use crate::handshake::{Handshake, HandshakeResult};
 use crate::service::Builder;
 
@@ -26,7 +26,7 @@ use super::{codec, Session};
 #[derive(Clone)]
 pub struct Client<Io, St> {
     keep_alive: u16,
-    inflight: usize,
+    max_receive: u16,
     connect: codec::Connect,
     _t: PhantomData<(Io, St)>,
 }
@@ -39,7 +39,7 @@ where
     pub fn new(client_id: ByteString) -> Self {
         Client {
             keep_alive: 30,
-            inflight: 15,
+            max_receive: 16,
             connect: codec::Connect { client_id, ..Default::default() },
             _t: PhantomData,
         }
@@ -79,11 +79,12 @@ where
         self
     }
 
-    /// Number of in-flight concurrent messages.
+    /// Set `receive max`
     ///
-    /// in-flight is set to 15 messages
-    pub fn inflight(mut self, val: usize) -> Self {
-        self.inflight = val;
+    /// Number of in-flight publish packets. By default receive max is set to 15 packets.
+    /// To disable timeout set value to 0.
+    pub fn receive_max(mut self, val: u16) -> Self {
+        self.max_receive = val;
         self
     }
 
@@ -106,7 +107,7 @@ where
                     .map_err(|_| unreachable!()),
             ),
             keep_alive: self.keep_alive.into(),
-            inflight: self.inflight,
+            max_receive: self.max_receive,
             _t: PhantomData,
         }
     }
@@ -116,7 +117,7 @@ pub struct ServiceBuilder<Io, St, C: Service> {
     state: Rc<C>,
     packet: codec::Connect,
     keep_alive: u64,
-    inflight: usize,
+    max_receive: u16,
     control: boxed::BoxServiceFactory<
         Session<St>,
         ControlPacket<C::Error>,
@@ -153,13 +154,16 @@ where
             connect: self.state,
             packet: self.packet,
             keep_alive: self.keep_alive,
-            inflight: self.inflight,
+            max_receive: self.max_receive,
             _t: PhantomData,
         })
         .build(factory(
-            service.into_factory().map_err(MqttError::Service).map_init_err(MqttError::Service),
+            service.into_factory()
+                .map_err(<C::Error>::from)
+                .map_init_err(MqttError::Service),
             self.control,
             0,
+            16,
         ))
     }
 }
@@ -168,7 +172,7 @@ struct ConnectService<Io, St, C> {
     connect: Rc<C>,
     packet: codec::Connect,
     keep_alive: u64,
-    inflight: usize,
+    max_receive: u16,
     _t: PhantomData<(Io, St)>,
 }
 
@@ -199,7 +203,10 @@ where
         let srv = self.connect.clone();
         let packet = self.packet.clone();
         let keep_alive = Duration::from_secs(self.keep_alive as u64);
-        let inflight = self.inflight;
+        let max_receive = self.max_receive;
+        if max_receive > 0 {
+            packet.receive_max = Some(NonZeroU16::new(max_receive).unwrap())
+        }
 
         // send Connect packet
         async move {
@@ -219,8 +226,11 @@ where
             match packet {
                 codec::Packet::ConnectAck(packet) => {
                     let (tx, rx) = mpsc::channel();
-                    let sink = MqttSink::new(tx);
-                    let ack = ConnectAck { sink, inflight, packet, io: framed };
+                    let sink = MqttSink::new(
+                        tx,
+                        packet.receive_max.map(|v| v.get()).unwrap_or(16) as usize,
+                    );
+                    let ack = ConnectAck { sink, packet, io: framed };
                     Ok(srv
                         .as_ref()
                         .call(ack)
@@ -228,7 +238,10 @@ where
                         .map_err(MqttError::Service)
                         .map(move |ack| ack.io.out(rx).state(ack.state))?)
                 }
-                p => Err(MqttError::Unexpected(p.packet_type(), "Expected CONNECT-ACK packet")),
+                p => Err(MqttError::Protocol(ProtocolError::Unexpected(
+                    p.packet_type(),
+                    "Expected CONNECT-ACK packet",
+                ))),
             }
         }
         .boxed_local()
@@ -238,7 +251,6 @@ where
 pub struct ConnectAck<Io> {
     io: HandshakeResult<Io, (), codec::Codec, mpsc::Receiver<codec::Packet>>,
     sink: MqttSink,
-    inflight: usize,
     packet: codec::ConnectAck,
 }
 
@@ -264,7 +276,7 @@ impl<Io> ConnectAck<Io> {
     #[inline]
     /// Set connection state and create result object
     pub fn state<St>(self, state: St) -> ConnectAckResult<Io, St> {
-        ConnectAckResult { io: self.io, state: Session::new(state, self.sink, self.inflight) }
+        ConnectAckResult { io: self.io, state: Session::new(state, self.sink) }
     }
 }
 
diff --git a/src/v5/mod.rs b/src/v5/mod.rs
index c862f0d3..1a96946f 100644
--- a/src/v5/mod.rs
+++ b/src/v5/mod.rs
@@ -1,6 +1,6 @@
 //! MQTT 3.1.1 Client/Server framework
 
-//pub mod client;
+// pub mod client;
 pub mod codec;
 mod connect;
 pub mod control;
@@ -13,7 +13,7 @@ mod sink;
 
 pub type Session<St> = crate::Session<MqttSink, St>;
 
-//pub use self::client::Client;
+// pub use self::client::Client;
 pub use self::connect::{Connect, ConnectAck};
 pub use self::control::{ControlPacket, ControlResult};
 pub use self::publish::{Publish, PublishAck};
diff --git a/src/v5/sink.rs b/src/v5/sink.rs
index 621711c1..be4a698a 100644
--- a/src/v5/sink.rs
+++ b/src/v5/sink.rs
@@ -1,5 +1,4 @@
-use std::task::{Context, Poll};
-use std::{cell::RefCell, collections::VecDeque, fmt, num::NonZeroU16, pin::Pin, rc::Rc};
+use std::{cell::RefCell, collections::VecDeque, fmt, num::NonZeroU16, rc::Rc};
 
 use bytes::Bytes;
 use bytestring::ByteString;