diff --git a/src/java/davmail/exchange/ExchangeSession.java b/src/java/davmail/exchange/ExchangeSession.java
index 5006a24b..46bfcbfb 100644
--- a/src/java/davmail/exchange/ExchangeSession.java
+++ b/src/java/davmail/exchange/ExchangeSession.java
@@ -729,6 +729,8 @@ public abstract class ExchangeSession {
         IMAP_MESSAGE_ATTRIBUTES.add("deleted");
         IMAP_MESSAGE_ATTRIBUTES.add("date");
         IMAP_MESSAGE_ATTRIBUTES.add("lastmodified");
+        // OSX IMAP requests content-class
+        IMAP_MESSAGE_ATTRIBUTES.add("contentclass");
     }
 
     protected static final Set<String> UID_MESSAGE_ATTRIBUTES = new HashSet<String>();
@@ -1632,6 +1634,10 @@ public abstract class ExchangeSession {
          * Message uid.
          */
         public String uid;
+        /**
+         * Message content class.
+         */
+        public String contentClass;
         /**
          * Message IMAP uid, unique in folder (x0e230003).
          */
diff --git a/src/java/davmail/exchange/dav/DavExchangeSession.java b/src/java/davmail/exchange/dav/DavExchangeSession.java
index 19001363..a5f779da 100644
--- a/src/java/davmail/exchange/dav/DavExchangeSession.java
+++ b/src/java/davmail/exchange/dav/DavExchangeSession.java
@@ -1996,6 +1996,7 @@ public class DavExchangeSession extends ExchangeSession {
         message.permanentUrl = getURLPropertyIfExists(properties, "permanenturl");
         message.size = getIntPropertyIfExists(properties, "messageSize");
         message.uid = getPropertyIfExists(properties, "uid");
+        message.contentClass = getPropertyIfExists(properties, "contentclass");
         message.imapUid = getLongPropertyIfExists(properties, "imapUid");
         message.read = "1".equals(getPropertyIfExists(properties, "read"));
         message.junk = "1".equals(getPropertyIfExists(properties, "junk"));
diff --git a/src/java/davmail/exchange/ews/EwsExchangeSession.java b/src/java/davmail/exchange/ews/EwsExchangeSession.java
index 07f07d47..610a8df4 100644
--- a/src/java/davmail/exchange/ews/EwsExchangeSession.java
+++ b/src/java/davmail/exchange/ews/EwsExchangeSession.java
@@ -568,6 +568,7 @@ public class EwsExchangeSession extends ExchangeSession {
 
         message.size = response.getInt(Field.get("messageSize").getResponseName());
         message.uid = response.get(Field.get("uid").getResponseName());
+        message.contentClass = response.get(Field.get("contentclass").getResponseName());
         message.imapUid = response.getLong(Field.get("imapUid").getResponseName());
         message.read = response.getBoolean(Field.get("read").getResponseName());
         message.junk = response.getBoolean(Field.get("junk").getResponseName());
diff --git a/src/java/davmail/imap/ImapConnection.java b/src/java/davmail/imap/ImapConnection.java
index 5ff0619a..a5cd7ce3 100644
--- a/src/java/davmail/imap/ImapConnection.java
+++ b/src/java/davmail/imap/ImapConnection.java
@@ -418,7 +418,7 @@ public class ImapConnection extends AbstractConnection {
                                                     session.moveMessage(message, targetName);
                                                 }
                                             }
-                                            sendClient(commandId + " OK "+command+" completed");
+                                            sendClient(commandId + " OK " + command + " completed");
                                         }
                                     } catch (HttpException e) {
                                         sendClient(commandId + " NO " + e.getMessage());
@@ -753,8 +753,6 @@ public class ImapConnection extends AbstractConnection {
                     InputStream partInputStream = null;
                     OutputStream partOutputStream = null;
 
-                    // load message
-                    MimeMessage mimeMessage = message.getMimeMessage();
                     // try to parse message part index
                     String partIndexString = StringUtil.getToken(param, "[", "]");
                     if ("".equals(partIndexString) || partIndexString == null) {
@@ -764,16 +762,23 @@ public class ImapConnection extends AbstractConnection {
                     } else if ("TEXT".equals(partIndexString)) {
                         // write message without headers
                         partOutputStream = new PartialOutputStream(baos, startIndex, maxSize);
-                        partInputStream = mimeMessage.getRawInputStream();
+                        partInputStream = message.getMimeMessage().getRawInputStream();
                     } else if ("RFC822.HEADER".equals(param) || partIndexString.startsWith("HEADER")) {
                         // Header requested fetch  headers
                         String[] requestedHeaders = getRequestedHeaders(partIndexString);
                         if (requestedHeaders != null) {
-                            Enumeration headerEnumeration = message.getMimeMessage().getMatchingHeaderLines(requestedHeaders);
-                            while (headerEnumeration.hasMoreElements()) {
-                                baos.write(((String) headerEnumeration.nextElement()).getBytes("UTF-8"));
+                            // OSX Lion special flags request
+                            if (requestedHeaders.length == 1 && "content-class".equals(requestedHeaders[0]) && message.contentClass != null) {
+                                baos.write(message.contentClass.getBytes("UTF-8"));
                                 baos.write(13);
                                 baos.write(10);
+                            } else {
+                                Enumeration headerEnumeration = message.getMimeMessage().getMatchingHeaderLines(requestedHeaders);
+                                while (headerEnumeration.hasMoreElements()) {
+                                    baos.write(((String) headerEnumeration.nextElement()).getBytes("UTF-8"));
+                                    baos.write(13);
+                                    baos.write(10);
+                                }
                             }
                         } else {
                             // write headers only
@@ -781,7 +786,7 @@ public class ImapConnection extends AbstractConnection {
                             partInputStream = message.getRawInputStream();
                         }
                     } else {
-                        MimePart bodyPart = mimeMessage;
+                        MimePart bodyPart = message.getMimeMessage();
                         String[] partIndexStrings = partIndexString.split("\\.");
                         for (String subPartIndexString : partIndexStrings) {
                             // ignore MIME subpart index, will return full part
diff --git a/src/test/davmail/imap/TestImap.java b/src/test/davmail/imap/TestImap.java
index 07f3ac8f..5886e9de 100644
--- a/src/test/davmail/imap/TestImap.java
+++ b/src/test/davmail/imap/TestImap.java
@@ -363,5 +363,29 @@ public class TestImap extends AbstractImapTestCase {
     }
 
 
+    public void testDraftMessageMessageId() throws IOException, InterruptedException, MessagingException {
+        testCreateFolder();
+        MimeMessage mimeMessage = new MimeMessage((Session) null);
+        mimeMessage.addHeader("to", Settings.getProperty("davmail.to"));
+        mimeMessage.setText("Test message");
+        mimeMessage.setSubject("Test subject");
+        ByteArrayOutputStream baos = new ByteArrayOutputStream();
+        mimeMessage.writeTo(baos);
+        byte[] content = baos.toByteArray();
+        writeLine(". APPEND testfolder (\\Seen \\Draft) {" + content.length + '}');
+        assertEquals("+ send literal data", readLine());
+        writeLine(new String(content));
+        assertEquals(". OK APPEND completed", readFullAnswer("."));
 
+        writeLine(". UID SEARCH UNDELETED (HEADER Message-ID "+mimeMessage.getMessageID().substring(1, mimeMessage.getMessageID().length()-1)+")");
+        assertEquals(". OK SEARCH completed", readFullAnswer("."));
+
+        testDeleteFolder();
+    }
+
+    public void testFetchOSX() throws IOException {
+        testSelectInbox();
+        writeLine(". FETCH 1:* (FLAGS UID BODY.PEEK[HEADER.FIELDS (content-class)])");
+        assertEquals(". OK FETCH completed", readFullAnswer("."));
+    }
 }