diff --git a/libsession/src/main/java/org/session/libsession/messaging/sending_receiving/MessageReceiver.kt b/libsession/src/main/java/org/session/libsession/messaging/sending_receiving/MessageReceiver.kt
index 5764d952b9..2b50dfd62d 100644
--- a/libsession/src/main/java/org/session/libsession/messaging/sending_receiving/MessageReceiver.kt
+++ b/libsession/src/main/java/org/session/libsession/messaging/sending_receiving/MessageReceiver.kt
@@ -1,4 +1,29 @@
-package org.session.messaging.sending_receiving
+package org.session.libsession.messaging.sending_receiving
 
 object MessageReceiver {
+    internal sealed class Error(val description: String) : Exception() {
+        object InvalidMessage: Error("Invalid message.")
+        object UnknownMessage: Error("Unknown message type.")
+        object UnknownEnvelopeType: Error("Unknown envelope type.")
+        object NoUserPublicKey: Error("Couldn't find user key pair.")
+        object NoData: Error("Received an empty envelope.")
+        object SenderBlocked: Error("Received a message from a blocked user.")
+        object NoThread: Error("Couldn't find thread for message.")
+        object SelfSend: Error("Message addressed at self.")
+        object ParsingFailed : Error("Couldn't parse ciphertext message.")
+        // Shared sender keys
+        object InvalidGroupPublicKey: Error("Invalid group public key.")
+        object NoGroupPrivateKey: Error("Missing group private key.")
+        object SharedSecretGenerationFailed: Error("Couldn't generate a shared secret.")
+
+        internal val isRetryable: Boolean = when (this) {
+            is InvalidMessage -> false
+            is UnknownMessage -> false
+            is UnknownEnvelopeType -> false
+            is NoData -> false
+            is SenderBlocked -> false
+            is SelfSend -> false
+            else -> true
+        }
+    }
 }
\ No newline at end of file
diff --git a/libsession/src/main/java/org/session/libsession/messaging/sending_receiving/MessageReceiverDelegate.kt b/libsession/src/main/java/org/session/libsession/messaging/sending_receiving/MessageReceiverDelegate.kt
index d3f37719d3..8312f2c674 100644
--- a/libsession/src/main/java/org/session/libsession/messaging/sending_receiving/MessageReceiverDelegate.kt
+++ b/libsession/src/main/java/org/session/libsession/messaging/sending_receiving/MessageReceiverDelegate.kt
@@ -1,4 +1,4 @@
-package org.session.messaging.sending_receiving
+package org.session.libsession.messaging.sending_receiving
 
 interface MessageReceiverDelegate {
 }
\ No newline at end of file
diff --git a/libsession/src/main/java/org/session/libsession/messaging/sending_receiving/MessageSenderDelegate.kt b/libsession/src/main/java/org/session/libsession/messaging/sending_receiving/MessageSenderDelegate.kt
index cee5622c47..2cdcb4d206 100644
--- a/libsession/src/main/java/org/session/libsession/messaging/sending_receiving/MessageSenderDelegate.kt
+++ b/libsession/src/main/java/org/session/libsession/messaging/sending_receiving/MessageSenderDelegate.kt
@@ -1,4 +1,4 @@
-package org.session.messaging.sending_receiving
+package org.session.libsession.messaging.sending_receiving
 
 interface MessageSenderDelegate {
 }
\ No newline at end of file