diff --git a/build.gradle b/build.gradle
index 4e1990b..f4d774a 100644
--- a/build.gradle
+++ b/build.gradle
@@ -76,6 +76,7 @@ dependencies {
 
     implementation group: 'it.unimi.dsi', name: 'fastutil-core', version: '8.5.18'
     implementation group: 'org.reflections', name: 'reflections', version: '0.10.2'
+    implementation group: 'com.esotericsoftware', name: 'reflectasm', version: '1.11.9'
 
     implementation group: 'com.google.code.gson', name: 'gson', version: '2.10.1'
     implementation group: 'us.hebi.quickbuf', name: 'quickbuf-runtime', version: '1.4'
diff --git a/src/main/java/emu/nebula/Nebula.java b/src/main/java/emu/nebula/Nebula.java
index 82555b8..c5a73a3 100644
--- a/src/main/java/emu/nebula/Nebula.java
+++ b/src/main/java/emu/nebula/Nebula.java
@@ -14,6 +14,7 @@ import emu.nebula.command.CommandManager;
 import emu.nebula.data.ResourceLoader;
 import emu.nebula.database.DatabaseManager;
 import emu.nebula.game.GameContext;
+import emu.nebula.net.PacketHelper;
 import emu.nebula.server.HttpServer;
 import emu.nebula.util.Handbook;
 import emu.nebula.util.JsonUtils;
@@ -78,6 +79,8 @@ public class Nebula {
             if (generateHandbook) {
                 Handbook.generate();
             }
+            // Cache proto methods
+            PacketHelper.cacheProtos();
         }
 
         try {
diff --git a/src/main/java/emu/nebula/net/GameSession.java b/src/main/java/emu/nebula/net/GameSession.java
index 8356bf6..eb83b34 100644
--- a/src/main/java/emu/nebula/net/GameSession.java
+++ b/src/main/java/emu/nebula/net/GameSession.java
@@ -11,6 +11,7 @@ import emu.nebula.game.GameContext;
 import emu.nebula.game.account.Account;
 import emu.nebula.game.account.AccountHelper;
 import emu.nebula.game.player.Player;
+import emu.nebula.proto.Public.MailState;
 import emu.nebula.util.AeadHelper;
 import emu.nebula.util.Utils;
 import lombok.Getter;
@@ -143,10 +144,36 @@ public class GameSession {
 
     @SneakyThrows
     public byte[] encodeMsg(int msgId, ProtoMessage<?> proto) {
+        // Add any extra data
+        this.addNextPackage(proto);
+        
+        // Encode to message like normal
         return PacketHelper.encodeMsg(msgId, proto);
     }
     
     public byte[] encodeMsg(int msgId) {
         return PacketHelper.encodeMsg(msgId);
     }
+    
+    private void addNextPackage(ProtoMessage<?> proto) {
+        // Sanity check and make sure proto has a "nextPackage" field
+        if (this.getPlayer() == null || !PacketHelper.hasNextPackageMethod(proto)) {
+            return;
+        }
+        
+        // Update mail state flag
+        if (this.getPlayer().getMailbox().isNewState()) {
+            // Clear
+            this.getPlayer().getMailbox().clearNewState();
+            
+            // Send mail state notify
+            byte[] nextPackage = PacketHelper.encodeMsg(
+                    NetMsgId.mail_state_notify, 
+                    MailState.newInstance().setNew(true)
+            );
+            
+            // Set via reflection
+            PacketHelper.setNextPackage(proto, nextPackage);
+        }
+    }
 }
diff --git a/src/main/java/emu/nebula/net/PacketHelper.java b/src/main/java/emu/nebula/net/PacketHelper.java
index 3f81c86..1f9ddc0 100644
--- a/src/main/java/emu/nebula/net/PacketHelper.java
+++ b/src/main/java/emu/nebula/net/PacketHelper.java
@@ -1,10 +1,45 @@
 package emu.nebula.net;
 
+import org.reflections.Reflections;
+
+import com.esotericsoftware.reflectasm.MethodAccess;
+
+import emu.nebula.Nebula;
+import it.unimi.dsi.fastutil.objects.Object2IntMap;
+import it.unimi.dsi.fastutil.objects.Object2IntOpenHashMap;
 import lombok.SneakyThrows;
 import us.hebi.quickbuf.ProtoMessage;
 import us.hebi.quickbuf.ProtoSink;
 
 public class PacketHelper {
+    private static Object2IntMap<Class<?>> methodIndexCache = new Object2IntOpenHashMap<>();
+    
+    public static void cacheProtos() {
+        var classes = new Reflections(Nebula.class.getPackage().getName()).getSubTypesOf(ProtoMessage.class);
+        
+        for (var cls : classes) {
+            try {
+                var access = MethodAccess.get(cls);
+                int index = access.getIndex("setNextPackage");
+                methodIndexCache.put(cls, index);
+            } catch (Exception e) {
+                
+            }
+        }
+        
+        Nebula.getLogger().info("Cached " + methodIndexCache.size() + " proto methods.");
+    }
+    
+    public static boolean hasNextPackageMethod(Object obj) {
+        return methodIndexCache.containsKey(obj.getClass());
+    }
+    
+    public static void setNextPackage(ProtoMessage<?> proto, byte[] data) {
+        int index = methodIndexCache.getInt(proto.getClass());
+        MethodAccess.get(proto.getClass()).invoke(proto, index, data);
+    }
+    
+    // Packet encoding
 
     public static byte[] encodeMsg(int msgId, byte[] packet) {
         // Create data array
diff --git a/src/main/java/emu/nebula/server/handlers/HandlerPlayerPingReq.java b/src/main/java/emu/nebula/server/handlers/HandlerPlayerPingReq.java
index a6b1d47..cd0eea2 100644
--- a/src/main/java/emu/nebula/server/handlers/HandlerPlayerPingReq.java
+++ b/src/main/java/emu/nebula/server/handlers/HandlerPlayerPingReq.java
@@ -2,9 +2,7 @@ package emu.nebula.server.handlers;
 
 import emu.nebula.net.NetHandler;
 import emu.nebula.net.NetMsgId;
-import emu.nebula.net.PacketHelper;
 import emu.nebula.proto.PlayerPing.Pong;
-import emu.nebula.proto.Public.MailState;
 import emu.nebula.net.HandlerId;
 import emu.nebula.Nebula;
 import emu.nebula.net.GameSession;
@@ -18,20 +16,6 @@ public class HandlerPlayerPingReq extends NetHandler {
         var rsp = Pong.newInstance()
                 .setServerTs(Nebula.getCurrentTime());
         
-        // Update mail state flag
-        if (session.getPlayer().getMailbox().isNewState()) {
-            // Clear
-            session.getPlayer().getMailbox().clearNewState();
-            
-            // Send mail state notify
-            byte[] nextPackage = PacketHelper.encodeMsg(
-                    NetMsgId.mail_state_notify, 
-                    MailState.newInstance().setNew(true)
-            );
-            
-            rsp.setNextPackage(nextPackage);
-        }
-        
         return session.encodeMsg(NetMsgId.player_ping_succeed_ack, rsp);
     }