diff --git a/app/src/main/java/eu/faircode/email/MimeMessageEx.java b/app/src/main/java/eu/faircode/email/MimeMessageEx.java
index d6c7b7896d..8b8abb3eea 100644
--- a/app/src/main/java/eu/faircode/email/MimeMessageEx.java
+++ b/app/src/main/java/eu/faircode/email/MimeMessageEx.java
@@ -19,8 +19,6 @@ package eu.faircode.email;
     Copyright 2018-2019 by Marcel Bokhorst (M66B)
 */
 
-import java.io.InputStream;
-
 import javax.mail.MessagingException;
 import javax.mail.Session;
 import javax.mail.internet.MimeMessage;
@@ -33,11 +31,6 @@ public class MimeMessageEx extends MimeMessage {
         this.msgid = msgid;
     }
 
-    MimeMessageEx(Session session, InputStream is, String msgid) throws MessagingException {
-        super(session, is);
-        this.msgid = msgid;
-    }
-
     @Override
     public String getMessageID() throws MessagingException {
         if (this.msgid == null)
diff --git a/app/src/main/java/eu/faircode/email/ServiceSynchronize.java b/app/src/main/java/eu/faircode/email/ServiceSynchronize.java
index 07ba148061..1e2096b6de 100644
--- a/app/src/main/java/eu/faircode/email/ServiceSynchronize.java
+++ b/app/src/main/java/eu/faircode/email/ServiceSynchronize.java
@@ -1848,14 +1848,15 @@ public class ServiceSynchronize extends LifecycleService {
             imessage.writeTo(bos);
 
             // Deserialize target message
-            // Make sure the message has a message ID
             ByteArrayInputStream bis = new ByteArrayInputStream(bos.toByteArray());
-            String msgid = message.msgid;
-            if (msgid == null) {
-                msgid = EntityMessage.generateMessageId();
+            Message icopy = new MimeMessage(isession, bis);
+
+            // Make sure the message has a message ID
+            if (message.msgid == null) {
+                String msgid = EntityMessage.generateMessageId();
                 Log.i(target.name + " generated message id=" + msgid);
+                icopy.setHeader("Message-ID", msgid);
             }
-            Message icopy = new MimeMessageEx(isession, bis, msgid);
 
             try {
                 // Needed to read flags
@@ -2203,11 +2204,15 @@ public class ServiceSynchronize extends LifecycleService {
             return uids[0].uid;
         } else {
             ifolder.appendMessages(new Message[]{imessage});
+
             long uid = -1;
-            Message[] messages = ifolder.search(new MessageIDTerm(imessage.getMessageID()));
+            String msgid = imessage.getMessageID();
+            Log.i("Searching for appended msgid=" + msgid);
+            Message[] messages = ifolder.search(new MessageIDTerm(msgid));
             if (messages != null)
                 for (Message iappended : messages) {
                     long muid = ifolder.getUID(iappended);
+                    Log.i("Found appended uid=" + muid);
                     // RFC3501: Unique identifiers are assigned in a strictly ascending fashion
                     if (muid > uid)
                         uid = muid;