diff --git a/src/main/java/dslab/mailbox/DMTPConnection.java b/src/main/java/dslab/mailbox/DMTPConnection.java
index d52d8df..526814d 100644
--- a/src/main/java/dslab/mailbox/DMTPConnection.java
+++ b/src/main/java/dslab/mailbox/DMTPConnection.java
@@ -128,9 +128,23 @@ public class DMTPConnection implements Runnable {
     private synchronized void storeMessage() {
         logger.info("Storing message " + msg.toString());
         this.msg.setId(MailboxServer.id++);
+        boolean alreadyPresent;
         for (Email recipient : this.msg.getTo()) {
+            alreadyPresent = false;
+            logger.info("storeMessage(): checking if msg " + msg.listMessage() + " already exists for recipient " + recipient.toString());
             if (this.messageStorage.containsKey(recipient)) {
-                this.messageStorage.get(recipient).add(this.msg);
+                // Check if message already exists for user
+                for (Message m : this.messageStorage.get(recipient)) {
+                    if (this.msg.getId().equals(m.getId())) {
+                        logger.info("storeMessage(): msg " + msg.listMessage() + " already exists for recipient " + recipient.toString());
+                        alreadyPresent = true;
+                        break;
+                    }
+                }
+                // Save only if message doesn't already exist
+                if (!alreadyPresent) {
+                    this.messageStorage.get(recipient).add(this.msg);
+                }
             }
         }
         this.msg = new Message();
diff --git a/src/main/java/dslab/transfer/TransferServer.java b/src/main/java/dslab/transfer/TransferServer.java
index 1b6dac6..e726a4a 100644
--- a/src/main/java/dslab/transfer/TransferServer.java
+++ b/src/main/java/dslab/transfer/TransferServer.java
@@ -157,6 +157,9 @@ public class TransferServer implements ITransferServer, Runnable {
                     logger.info("Queue not empty. Processing message...");
                     Message msg = blockingQueue.take();
                     logger.info("Took message " + msg.toString() + " from queue");
+                    HashMap<String, Boolean> sent = new HashMap<>();
+                    sent.put("earth.planet", false);
+                    sent.put("univer.ze", false);
                     for (Email recipient : msg.getTo()) {
                         logger.info("msg.getTo() contains: " + msg.getTo().toString());
                         logger.info("Trying to send message to " + recipient.toString());
@@ -164,7 +167,10 @@ public class TransferServer implements ITransferServer, Runnable {
                         try {
                             port = domainLookup(recipient);
                             logger.info("Domain lookup successful. Port is: " + port);
-                            replayMessage(msg, port);
+                            if (!sent.get(recipient.getDomain())) {
+                                replayMessage(msg, port);
+                                sent.put(recipient.getDomain(), true);
+                            }
                         } catch (UnknownDomain e) {
                             sendErrorMail(msg, e.getMessage());
                         }