diff --git a/core/src/main/java/haveno/core/support/SupportManager.java b/core/src/main/java/haveno/core/support/SupportManager.java
index 5c2e8b6f..ecbf5302 100644
--- a/core/src/main/java/haveno/core/support/SupportManager.java
+++ b/core/src/main/java/haveno/core/support/SupportManager.java
@@ -29,8 +29,6 @@ import haveno.core.support.messages.ChatMessage;
 import haveno.core.support.messages.SupportMessage;
 import haveno.core.trade.Trade;
 import haveno.core.trade.TradeManager;
-import haveno.core.trade.protocol.TradeProtocol;
-import haveno.core.trade.protocol.TradeProtocol.MailboxMessageComparator;
 import haveno.core.xmr.wallet.XmrWalletService;
 import haveno.network.p2p.AckMessage;
 import haveno.network.p2p.AckMessageSourceType;
@@ -40,10 +38,10 @@ import haveno.network.p2p.P2PService;
 import haveno.network.p2p.SendMailboxMessageListener;
 import haveno.network.p2p.mailbox.MailboxMessage;
 import haveno.network.p2p.mailbox.MailboxMessageService;
+import haveno.network.p2p.mailbox.MailboxMessageService.DecryptedMessageWithPubKeyComparator;
 import lombok.extern.slf4j.Slf4j;
 
 import javax.annotation.Nullable;
-import java.util.Comparator;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
@@ -82,9 +80,9 @@ public abstract class SupportManager {
 
         // We get first the message handler called then the onBootstrapped
         p2PService.addDecryptedDirectMessageListener((decryptedMessageWithPubKey, senderAddress) -> {
-            if (isReady()) applyDirectMessage(decryptedMessageWithPubKey);
-            else {
-                synchronized (lock) {
+            synchronized (lock) {
+                if (isReady()) applyDirectMessage(decryptedMessageWithPubKey);
+                else {
                     // As decryptedDirectMessageWithPubKeys is a CopyOnWriteArraySet we do not need to check if it was already stored
                     decryptedDirectMessageWithPubKeys.add(decryptedMessageWithPubKey);
                     tryApplyMessages();
@@ -92,9 +90,9 @@ public abstract class SupportManager {
             }
         });
         mailboxMessageService.addDecryptedMailboxListener((decryptedMessageWithPubKey, senderAddress) -> {
-            if (isReady()) applyMailboxMessage(decryptedMessageWithPubKey);
-            else {
-                synchronized (lock) {
+            synchronized (lock) {
+                if (isReady()) applyMailboxMessage(decryptedMessageWithPubKey);
+                else {
                     // As decryptedMailboxMessageWithPubKeys is a CopyOnWriteArraySet we do not need to check if it was already stored
                     decryptedDirectMessageWithPubKeys.add(decryptedMessageWithPubKey);
                     tryApplyMessages();
@@ -395,22 +393,4 @@ public abstract class SupportManager {
             mailboxMessageService.removeMailboxMsg(ackMessage);
         }
     }
-
-    private static class DecryptedMessageWithPubKeyComparator implements Comparator<DecryptedMessageWithPubKey> {
-
-        MailboxMessageComparator mailboxMessageComparator;
-        public DecryptedMessageWithPubKeyComparator() {
-            mailboxMessageComparator = new TradeProtocol.MailboxMessageComparator();
-        }
-
-        @Override
-        public int compare(DecryptedMessageWithPubKey m1, DecryptedMessageWithPubKey m2) {
-            if (m1.getNetworkEnvelope() instanceof MailboxMessage) {
-                if (m2.getNetworkEnvelope() instanceof MailboxMessage) return mailboxMessageComparator.compare((MailboxMessage) m1.getNetworkEnvelope(), (MailboxMessage) m2.getNetworkEnvelope());
-                else return 1;
-            } else {
-                return m2.getNetworkEnvelope() instanceof MailboxMessage ? -1 : 0;
-            }
-        }
-    }
 }
diff --git a/core/src/main/java/haveno/core/support/dispute/DisputeManager.java b/core/src/main/java/haveno/core/support/dispute/DisputeManager.java
index faed3a89..6a1f69c9 100644
--- a/core/src/main/java/haveno/core/support/dispute/DisputeManager.java
+++ b/core/src/main/java/haveno/core/support/dispute/DisputeManager.java
@@ -354,6 +354,7 @@ public abstract class DisputeManager<T extends DisputeList<Dispute>> extends Sup
                     disputeList.add(dispute);
                 }
 
+                // create dispute opened message
                 NodeAddress agentNodeAddress = getAgentNodeAddress(dispute);
                 DisputeOpenedMessage disputeOpenedMessage = new DisputeOpenedMessage(dispute,
                         p2PService.getAddress(),
@@ -367,6 +368,8 @@ public abstract class DisputeManager<T extends DisputeList<Dispute>> extends Sup
                         disputeOpenedMessage.getTradeId(), disputeOpenedMessage.getUid(),
                         chatMessage.getUid());
                 recordPendingMessage(disputeOpenedMessage.getClass().getSimpleName());
+
+                // send dispute opened message
                 mailboxMessageService.sendEncryptedMailboxMessage(agentNodeAddress,
                         dispute.getAgentPubKeyRing(),
                         disputeOpenedMessage,
@@ -436,7 +439,7 @@ public abstract class DisputeManager<T extends DisputeList<Dispute>> extends Sup
     // arbitrator receives dispute opened message from opener, opener's peer receives from arbitrator
     protected void handleDisputeOpenedMessage(DisputeOpenedMessage message) {
         Dispute dispute = message.getDispute();
-        log.info("{}.onDisputeOpenedMessage() with trade {}, dispute {}", getClass().getSimpleName(), dispute.getTradeId(), dispute.getId());
+        log.info("Processing {} with trade {}, dispute {}", message.getClass().getSimpleName(), dispute.getTradeId(), dispute.getId());
 
         // get trade
         Trade trade = tradeManager.getTrade(dispute.getTradeId());
@@ -467,6 +470,7 @@ public abstract class DisputeManager<T extends DisputeList<Dispute>> extends Sup
                     DisputeValidation.validateSenderNodeAddress(dispute, message.getSenderNodeAddress());
                     //DisputeValidation.testIfDisputeTriesReplay(dispute, disputeList.getList());
                 } catch (DisputeValidation.ValidationException e) {
+                    e.printStackTrace();
                     validationExceptions.add(e);
                     throw e;
                 }
@@ -476,6 +480,7 @@ public abstract class DisputeManager<T extends DisputeList<Dispute>> extends Sup
                 try {
                     DisputeValidation.validatePaymentAccountPayload(dispute);
                 } catch (Exception e) {
+                    e.printStackTrace();
                     log.warn(e.getMessage());
                     trade.prependErrorMessage(e.getMessage());
                 }
@@ -499,7 +504,7 @@ public abstract class DisputeManager<T extends DisputeList<Dispute>> extends Sup
 
                 // update multisig hex
                 if (message.getUpdatedMultisigHex() != null) sender.setUpdatedMultisigHex(message.getUpdatedMultisigHex());
-                trade.importMultisigHex();
+                if (trade.walletExists()) trade.importMultisigHex();
 
                 // add chat message with price info
                 if (trade instanceof ArbitratorTrade) addPriceInfoMessage(dispute, 0);
@@ -518,8 +523,7 @@ public abstract class DisputeManager<T extends DisputeList<Dispute>> extends Sup
                             errorMessage = null;
                         } else {
                             // valid case if both have opened a dispute and agent was not online
-                            log.debug("We got a dispute already open for that trade and trading peer. TradeId = {}",
-                                    dispute.getTradeId());
+                            log.debug("We got a dispute already open for that trade and trading peer. TradeId = {}", dispute.getTradeId());
                         }
 
                         // add chat message with mediation info if applicable
@@ -529,6 +533,7 @@ public abstract class DisputeManager<T extends DisputeList<Dispute>> extends Sup
                     }
                 }
             } catch (Exception e) {
+                e.printStackTrace();
                 errorMessage = e.getMessage();
                 log.warn(errorMessage);
                 if (trade != null) trade.setErrorMessage(errorMessage);
diff --git a/core/src/main/java/haveno/core/support/dispute/arbitration/ArbitrationManager.java b/core/src/main/java/haveno/core/support/dispute/arbitration/ArbitrationManager.java
index aadea08f..57908663 100644
--- a/core/src/main/java/haveno/core/support/dispute/arbitration/ArbitrationManager.java
+++ b/core/src/main/java/haveno/core/support/dispute/arbitration/ArbitrationManager.java
@@ -116,7 +116,7 @@ public final class ArbitrationManager extends DisputeManager<ArbitrationDisputeL
             log.info("Received {} from {} with tradeId {} and uid {}",
                     message.getClass().getSimpleName(), message.getSenderNodeAddress(), message.getTradeId(), message.getUid());
 
-            new Thread(() -> {
+            HavenoUtils.runTask(message.getTradeId(), () -> {
                 if (message instanceof DisputeOpenedMessage) {
                     handleDisputeOpenedMessage((DisputeOpenedMessage) message);
                 } else if (message instanceof ChatMessage) {
@@ -126,7 +126,7 @@ public final class ArbitrationManager extends DisputeManager<ArbitrationDisputeL
                 } else {
                     log.warn("Unsupported message at dispatchMessage. message={}", message);
                 }
-            }).start();
+            });
         }
     }
 
@@ -221,7 +221,7 @@ public final class ArbitrationManager extends DisputeManager<ArbitrationDisputeL
                 String summaryText = chatMessage.getMessage();
                 if (summaryText == null || summaryText.isEmpty()) throw new IllegalArgumentException("Summary text for dispute is missing, tradeId=" + tradeId + (dispute == null ? "" : ", disputeId=" + dispute.getId()));
                 if (dispute != null) DisputeSummaryVerification.verifySignature(summaryText, dispute.getAgentPubKeyRing()); // use dispute's arbitrator pub key ring
-                else DisputeSummaryVerification.verifySignature(summaryText, arbitratorManager); // verify using registered arbitrator (will fail is arbitrator is unregistered)
+                else DisputeSummaryVerification.verifySignature(summaryText, arbitratorManager); // verify using registered arbitrator (will fail if arbitrator is unregistered)
 
                 // save dispute closed message for reprocessing
                 trade.getArbitrator().setDisputeClosedMessage(disputeClosedMessage);
@@ -253,11 +253,9 @@ public final class ArbitrationManager extends DisputeManager<ArbitrationDisputeL
                     trade.saveWallet();
                 }
 
-                // import multisig hex
-                if (trade.walletExists()) {
-                    if (disputeClosedMessage.getUpdatedMultisigHex() != null) trade.getArbitrator().setUpdatedMultisigHex(disputeClosedMessage.getUpdatedMultisigHex());
-                    trade.importMultisigHex();
-                }
+                // update multisig hex
+                if (disputeClosedMessage.getUpdatedMultisigHex() != null) trade.getArbitrator().setUpdatedMultisigHex(disputeClosedMessage.getUpdatedMultisigHex());
+                if (trade.walletExists()) trade.importMultisigHex();
 
                 // attempt to sign and publish dispute payout tx if given and not already published
                 if (disputeClosedMessage.getUnsignedPayoutTxHex() != null && !trade.isPayoutPublished()) {
@@ -270,7 +268,9 @@ public final class ArbitrationManager extends DisputeManager<ArbitrationDisputeL
                     }
 
                     // sign and publish dispute payout tx if peer still has not published
-                    if (!trade.isPayoutPublished()) {
+                    if (trade.isPayoutPublished()) {
+                        log.info("Dispute payout tx already published for {} {}", trade.getClass().getSimpleName(), trade.getId());
+                    } else {
                         try {
                             log.info("Signing and publishing dispute payout tx for {} {}", trade.getClass().getSimpleName(), trade.getId());
                             signAndPublishDisputePayoutTx(trade);
@@ -284,14 +284,17 @@ public final class ArbitrationManager extends DisputeManager<ArbitrationDisputeL
                                 throw new RuntimeException("Failed to sign and publish dispute payout tx from arbitrator: " + e.getMessage() + ". TradeId = " + tradeId);
                             }
                         }
-                    } else {
-                        log.info("Dispute payout tx already published for {} {}", trade.getClass().getSimpleName(), trade.getId());
                     }
                 } else {
                     if (trade.isPayoutPublished()) log.info("Dispute payout tx already published for {} {}", trade.getClass().getSimpleName(), trade.getId());
                     else if (disputeClosedMessage.getUnsignedPayoutTxHex() == null) log.info("{} did not receive unsigned dispute payout tx for trade {} because the arbitrator did not have their updated multisig info (can happen if trader went offline after trade started)", trade.getClass().getSimpleName(), trade.getId());
                 }
 
+                // complete disputed trade
+                if (trade.isPayoutPublished()) {
+                    tradeManager.closeDisputedTrade(trade.getId(), Trade.DisputeState.DISPUTE_CLOSED);
+                }
+
                 // We use the chatMessage as we only persist those not the DisputeClosedMessage.
                 // If we would use the DisputeClosedMessage we could not lookup for the msg when we receive the AckMessage.
                 sendAckMessage(chatMessage, dispute.getAgentPubKeyRing(), true, null);
diff --git a/core/src/main/java/haveno/core/trade/HavenoUtils.java b/core/src/main/java/haveno/core/trade/HavenoUtils.java
index 8df6190d..9991c66e 100644
--- a/core/src/main/java/haveno/core/trade/HavenoUtils.java
+++ b/core/src/main/java/haveno/core/trade/HavenoUtils.java
@@ -46,8 +46,10 @@ import java.text.DecimalFormatSymbols;
 import java.text.SimpleDateFormat;
 import java.util.ArrayList;
 import java.util.Collection;
+import java.util.HashMap;
 import java.util.List;
 import java.util.Locale;
+import java.util.Map;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
@@ -75,6 +77,7 @@ public class HavenoUtils {
     public static final SimpleDateFormat DATE_FORMAT = new SimpleDateFormat("dd-MM-yyyy HH:mm:ss");
     private static final int POOL_SIZE = 10;
     private static final ExecutorService POOL = Executors.newFixedThreadPool(POOL_SIZE);
+    private static final Map<String, ExecutorService> POOLS = new HashMap<>();
 
     // TODO: better way to share references?
     public static ArbitrationManager arbitrationManager;
@@ -467,6 +470,22 @@ public class HavenoUtils {
         }
     }
 
+    public static Future<?> runTask(String threadId, Runnable task) {
+        synchronized (POOLS) {
+            if (!POOLS.containsKey(threadId)) POOLS.put(threadId, Executors.newFixedThreadPool(1));
+            return POOLS.get(threadId).submit(task);
+        }
+    }
+
+    public static void removeThreadId(String threadId) {
+        synchronized (POOLS) {
+            if (POOLS.containsKey(threadId)) {
+                POOLS.get(threadId).shutdown();
+                POOLS.remove(threadId);
+            }
+        }
+    }
+
     /**
      * Submit tasks to a global thread pool.
      */
diff --git a/core/src/main/java/haveno/core/trade/TradeManager.java b/core/src/main/java/haveno/core/trade/TradeManager.java
index a10389c0..b4f55dc0 100644
--- a/core/src/main/java/haveno/core/trade/TradeManager.java
+++ b/core/src/main/java/haveno/core/trade/TradeManager.java
@@ -54,6 +54,7 @@ import haveno.core.trade.messages.InitMultisigRequest;
 import haveno.core.trade.messages.InitTradeRequest;
 import haveno.core.trade.messages.SignContractRequest;
 import haveno.core.trade.messages.SignContractResponse;
+import haveno.core.trade.messages.TradeMessage;
 import haveno.core.trade.protocol.ArbitratorProtocol;
 import haveno.core.trade.protocol.MakerProtocol;
 import haveno.core.trade.protocol.ProcessModel;
@@ -232,7 +233,9 @@ public class TradeManager implements PersistedDataHost, DecryptedDirectMessageLi
     @Override
     public void onDirectMessage(DecryptedMessageWithPubKey message, NodeAddress peer) {
         NetworkEnvelope networkEnvelope = message.getNetworkEnvelope();
-        new Thread(() -> {
+        if (!(networkEnvelope instanceof TradeMessage)) return;
+        String tradeId = ((TradeMessage) networkEnvelope).getTradeId();
+        HavenoUtils.runTask(tradeId, () -> {
             if (networkEnvelope instanceof InitTradeRequest) {
                 handleInitTradeRequest((InitTradeRequest) networkEnvelope, peer);
             } else if (networkEnvelope instanceof InitMultisigRequest) {
@@ -246,7 +249,7 @@ public class TradeManager implements PersistedDataHost, DecryptedDirectMessageLi
             } else if (networkEnvelope instanceof DepositResponse) {
                 handleDepositResponse((DepositResponse) networkEnvelope, peer);
             }
-        }).start();
+        });
     }
 
 
@@ -1202,6 +1205,7 @@ public class TradeManager implements PersistedDataHost, DecryptedDirectMessageLi
 
             // remove trade
             tradableList.remove(trade);
+            HavenoUtils.removeThreadId(trade.getId());
 
             // unregister and persist
             p2PService.removeDecryptedDirectMessageListener(getTradeProtocol(trade));
diff --git a/core/src/main/java/haveno/core/trade/protocol/TradeProtocol.java b/core/src/main/java/haveno/core/trade/protocol/TradeProtocol.java
index 53db1196..2d075430 100644
--- a/core/src/main/java/haveno/core/trade/protocol/TradeProtocol.java
+++ b/core/src/main/java/haveno/core/trade/protocol/TradeProtocol.java
@@ -93,6 +93,11 @@ public abstract class TradeProtocol implements DecryptedDirectMessageListener, D
 
     private int reprocessPaymentReceivedMessageCount;
 
+    // set comparator for processing mailbox messages
+    static {
+        MailboxMessageService.setMailboxMessageComparator(new MailboxMessageComparator());
+    }
+
     ///////////////////////////////////////////////////////////////////////////////////////////
     // Constructor
     ///////////////////////////////////////////////////////////////////////////////////////////
@@ -245,12 +250,14 @@ public abstract class TradeProtocol implements DecryptedDirectMessageListener, D
         if (!trade.isCompleted()) processModel.getP2PService().addDecryptedDirectMessageListener(this);
 
         // initialize trade
-        trade.initialize(processModel.getProvider());
+        synchronized (trade) {
+            trade.initialize(processModel.getProvider());
 
-        // process mailbox messages
-        MailboxMessageService mailboxMessageService = processModel.getP2PService().getMailboxMessageService();
-        if (!trade.isCompleted()) mailboxMessageService.addDecryptedMailboxListener(this);
-        handleMailboxCollection(mailboxMessageService.getMyDecryptedMailboxMessages());
+            // process mailbox messages
+            MailboxMessageService mailboxMessageService = processModel.getP2PService().getMailboxMessageService();
+            if (!trade.isCompleted()) mailboxMessageService.addDecryptedMailboxListener(this);
+            handleMailboxCollection(mailboxMessageService.getMyDecryptedMailboxMessages());
+        }
 
         // send deposits confirmed message if applicable
         maybeSendDepositsConfirmedMessage();
@@ -477,18 +484,18 @@ public abstract class TradeProtocol implements DecryptedDirectMessageListener, D
                 handleTaskRunnerSuccess(peer, message);
                 return;
             }
+            if (trade.getPayoutTx() != null) {
+                log.warn("We received a PaymentSentMessage but we have already created the payout tx " +
+                                        "so we ignore the message. This can happen if the ACK message to the peer did not " +
+                                        "arrive and the peer repeats sending us the message. We send another ACK msg.");
+                sendAckMessage(peer, message, true, null);
+                removeMailboxMessageAfterProcessing(message);
+                return;
+            }
             latchTrade();
             expect(anyPhase(Trade.Phase.DEPOSITS_CONFIRMED, Trade.Phase.DEPOSITS_UNLOCKED)
                     .with(message)
-                    .from(peer)
-                    .preCondition(trade.getPayoutTx() == null,
-                            () -> {
-                                log.warn("We received a PaymentSentMessage but we have already created the payout tx " +
-                                        "so we ignore the message. This can happen if the ACK message to the peer did not " +
-                                        "arrive and the peer repeats sending us the message. We send another ACK msg.");
-                                sendAckMessage(peer, message, true, null);
-                                removeMailboxMessageAfterProcessing(message);
-                            }))
+                    .from(peer))
                     .setup(tasks(
                             ApplyFilter.class,
                             ProcessPaymentSentMessage.class,
diff --git a/p2p/src/main/java/haveno/network/p2p/mailbox/MailboxMessageService.java b/p2p/src/main/java/haveno/network/p2p/mailbox/MailboxMessageService.java
index 5d2ce5b7..09780edc 100644
--- a/p2p/src/main/java/haveno/network/p2p/mailbox/MailboxMessageService.java
+++ b/p2p/src/main/java/haveno/network/p2p/mailbox/MailboxMessageService.java
@@ -123,6 +123,7 @@ public class MailboxMessageService implements HashMapChangedListener, PersistedD
     private boolean isBootstrapped;
     private boolean allServicesInitialized;
     private boolean initAfterBootstrapped;
+    private static Comparator<MailboxMessage> mailboxMessageComparator;
 
     @Inject
     public MailboxMessageService(NetworkNode networkNode,
@@ -182,9 +183,11 @@ public class MailboxMessageService implements HashMapChangedListener, PersistedD
                                 // Those outdated messages would then stay in the network until TTL triggers removal.
                                 // By not applying large messages we reduce the impact of such cases at costs of extra loading costs if the message is still alive.
                                 if (serializedSize < MAX_SERIALIZED_SIZE) {
-                                    mailboxItemsByUid.put(mailboxItem.getUid(), mailboxItem);
-                                    mailboxMessageList.add(mailboxItem);
-                                    totalSize.getAndAdd(serializedSize);
+                                    synchronized (mailboxMessageList) {
+                                        mailboxItemsByUid.put(mailboxItem.getUid(), mailboxItem);
+                                        mailboxMessageList.add(mailboxItem);
+                                        totalSize.getAndAdd(serializedSize);
+                                    }
 
                                     // We add it to our map so that it get added to the excluded key set we send for
                                     // the initial data requests. So that helps to lower the load for mailbox messages at
@@ -330,9 +333,7 @@ public class MailboxMessageService implements HashMapChangedListener, PersistedD
      */
     public void removeMailboxMsg(MailboxMessage mailboxMessage) {
         if (isBootstrapped) {
-            // We need to delay a bit to not get a ConcurrentModificationException as we might iterate over
-            // mailboxMessageList while getting called.
-            UserThread.execute(() -> {
+            synchronized (mailboxMessageList) {
                 String uid = mailboxMessage.getUid();
                 if (!mailboxItemsByUid.containsKey(uid)) {
                     return;
@@ -349,7 +350,7 @@ public class MailboxMessageService implements HashMapChangedListener, PersistedD
                 // call removeMailboxItemFromMap here. The onRemoved only removes foreign mailBoxMessages.
                 log.trace("## removeMailboxMsg uid={}", uid);
                 removeMailboxItemFromLocalStore(uid);
-            });
+            }
         } else {
             // In case the network was not ready yet we try again later
             UserThread.runAfter(() -> removeMailboxMsg(mailboxMessage), 30);
@@ -397,7 +398,24 @@ public class MailboxMessageService implements HashMapChangedListener, PersistedD
                 .forEach(this::removeMailboxItemFromLocalStore);
     }
 
+    public static void setMailboxMessageComparator(Comparator<MailboxMessage> comparator) {
+        mailboxMessageComparator = comparator;
+    }
 
+    public static class DecryptedMessageWithPubKeyComparator implements Comparator<DecryptedMessageWithPubKey> {
+
+        @Override
+        public int compare(DecryptedMessageWithPubKey m1, DecryptedMessageWithPubKey m2) {
+            if (m1.getNetworkEnvelope() instanceof MailboxMessage) {
+                if (m2.getNetworkEnvelope() instanceof MailboxMessage) return mailboxMessageComparator.compare((MailboxMessage) m1.getNetworkEnvelope(), (MailboxMessage) m2.getNetworkEnvelope());
+                else return 1;
+            } else {
+                return m2.getNetworkEnvelope() instanceof MailboxMessage ? -1 : 0;
+            }
+        }
+    }
+
+    
     ///////////////////////////////////////////////////////////////////////////////////////////
     // Private
     ///////////////////////////////////////////////////////////////////////////////////////////
@@ -429,7 +447,7 @@ public class MailboxMessageService implements HashMapChangedListener, PersistedD
 
         Futures.addCallback(future, new FutureCallback<>() {
             public void onSuccess(Set<MailboxItem> decryptedMailboxMessageWithEntries) {
-                UserThread.execute(() -> decryptedMailboxMessageWithEntries.forEach(e -> handleMailboxItem(e)));
+                new Thread(() -> handleMailboxItems(decryptedMailboxMessageWithEntries)).start();
             }
 
             public void onFailure(@NotNull Throwable throwable) {
@@ -471,16 +489,42 @@ public class MailboxMessageService implements HashMapChangedListener, PersistedD
         return new MailboxItem(protectedMailboxStorageEntry, null);
     }
 
+    private void handleMailboxItems(Set<MailboxItem> mailboxItems) {
+
+        // sort mailbox items
+        List<MailboxItem> mailboxItemsSorted = mailboxItems.stream()
+                .filter(e -> !e.isMine())
+                .collect(Collectors.toList());
+        mailboxItemsSorted.addAll(mailboxItems.stream()
+                .filter(e -> e.isMine())
+                .sorted(new MailboxItemComparator())
+                .collect(Collectors.toList()));
+
+        // handle mailbox items
+        mailboxItemsSorted.forEach(e -> handleMailboxItem(e));
+    }
+
+    private static class MailboxItemComparator implements Comparator<MailboxItem> {
+        private DecryptedMessageWithPubKeyComparator comparator = new DecryptedMessageWithPubKeyComparator();
+
+        @Override
+        public int compare(MailboxItem m1, MailboxItem m2) {
+            return comparator.compare(m1.getDecryptedMessageWithPubKey(), m2.getDecryptedMessageWithPubKey());
+        }
+    }
+
     private void handleMailboxItem(MailboxItem mailboxItem) {
         String uid = mailboxItem.getUid();
-        if (!mailboxItemsByUid.containsKey(uid)) {
-            mailboxItemsByUid.put(uid, mailboxItem);
-            mailboxMessageList.add(mailboxItem);
-            log.trace("## handleMailboxItem uid={}\nhash={}",
-                    uid,
-                    P2PDataStorage.get32ByteHashAsByteArray(mailboxItem.getProtectedMailboxStorageEntry().getProtectedStoragePayload()));
+        synchronized (mailboxMessageList) {
+            if (!mailboxItemsByUid.containsKey(uid)) {
+                mailboxItemsByUid.put(uid, mailboxItem);
+                mailboxMessageList.add(mailboxItem);
+                log.trace("## handleMailboxItem uid={}\nhash={}",
+                        uid,
+                        P2PDataStorage.get32ByteHashAsByteArray(mailboxItem.getProtectedMailboxStorageEntry().getProtectedStoragePayload()));
 
-            requestPersistence();
+                requestPersistence();
+            }
         }
 
         // In case we had the item already stored we still prefer to apply it again to the domain.