diff --git a/mailnews/imap/public/nsIImapService.idl b/mailnews/imap/public/nsIImapService.idl
index 5f5b9c561616..b2b29dfe91d8 100644
--- a/mailnews/imap/public/nsIImapService.idl
+++ b/mailnews/imap/public/nsIImapService.idl
@@ -173,6 +173,8 @@ interface nsIImapService : nsISupports
                              out nsIURI aURL,
                              in nsISupports aCopyState);
   
+  void downloadMessagesForOffline(in string aMessageIds, in nsIMsgFolder aSrcFolder,
+                      in nsIMsgWindow   aMsgWindow);
   nsIURI moveFolder(in nsIEventQueue aClientEventQueue, 
                     in nsIMsgFolder aSrcFolder,
                     in nsIMsgFolder aDstFolder,
diff --git a/mailnews/imap/src/nsImapMailFolder.cpp b/mailnews/imap/src/nsImapMailFolder.cpp
index 6c158e432ab0..4a7f1dad3547 100644
--- a/mailnews/imap/src/nsImapMailFolder.cpp
+++ b/mailnews/imap/src/nsImapMailFolder.cpp
@@ -138,6 +138,7 @@ NS_IMPL_QUERY_HEAD(nsImapMailFolder)
     NS_IMPL_QUERY_BODY(nsIImapMiscellaneousSink)
     NS_IMPL_QUERY_BODY(nsIUrlListener)
     NS_IMPL_QUERY_BODY(nsIMsgFilterHitNotify)
+    NS_IMPL_QUERY_BODY(nsIStreamListener)
 NS_IMPL_QUERY_TAIL_INHERITING(nsMsgDBFolder)
 
 
@@ -2942,7 +2943,17 @@ nsImapMailFolder::SetupMsgWriteStream(const char * aNativeString, PRBool addDumm
 
 NS_IMETHODIMP nsImapMailFolder::DownloadMessagesForOffline(nsISupportsArray *messages)
 {
-  return NS_OK;
+  nsCAutoString messageIds;
+  nsMsgKeyArray srcKeyArray;
+
+  nsresult rv = BuildIdsAndKeyArray(messages, messageIds, srcKeyArray);
+  if (NS_FAILED(rv)) return rv;
+  NS_WITH_SERVICE(nsIImapService, imapService, kCImapService, &rv);
+  if (NS_FAILED(rv)) return rv;
+
+  SetNotifyDownloadedLines(PR_TRUE); // ### TODO need to clear this when we've finished
+  rv = imapService->DownloadMessagesForOffline(messageIds, this, nsnull);
+  return rv;
 }
 
 NS_IMETHODIMP
@@ -3041,16 +3052,16 @@ nsImapMailFolder::NormalEndMsgWriteStream(nsMsgKey uidOfMessage, PRBool markRead
 
   if (m_offlineHeader)
   {
-    PRUint32 newFlags;
-
     nsCOMPtr <nsIRandomAccessStore> randomStore;
     PRInt32 curStorePos;
     PRUint32 messageOffset;
+    nsMsgKey messageKey;
 
-    if (m_offlineHeader)
+    m_offlineHeader->GetMessageKey(&messageKey);
+    if (m_tempMessageStream)
       randomStore = do_QueryInterface(m_tempMessageStream);
 
-    m_offlineHeader->OrFlags(MSG_FLAG_OFFLINE, &newFlags);
+    mDatabase->MarkOffline(messageKey, PR_TRUE, nsnull);
     if (randomStore)
     {
       m_tempMessageStream->Flush();
@@ -3456,6 +3467,26 @@ nsImapMailFolder::SetContentModified(nsIImapUrl *aImapUrl, nsImapContentModified
   return aImapUrl->SetContentModified(modified);
 }
 
+// we provide this interface (nsIStreamListener) because the nsImapProtocol wants us to, in order
+// to hook up the mock channel and other stuff when downloading messages for offline use.
+// But we don't really need to do anything with these notifications because we use 
+// the nsIImapMesageSink interfaces ParseAdoptedMessageLine and NormalEndMsgWriteStream
+NS_IMETHODIMP nsImapMailFolder::OnDataAvailable(nsIChannel * /* aChannel */, nsISupports *ctxt, nsIInputStream *aIStream, PRUint32 sourceOffset, PRUint32 aLength)
+{
+	nsresult rv = NS_OK;
+	return rv;
+}
+
+NS_IMETHODIMP nsImapMailFolder::OnStartRequest(nsIChannel * aChannel, nsISupports *ctxt)
+{
+	return NS_OK;
+}
+
+NS_IMETHODIMP nsImapMailFolder::OnStopRequest(nsIChannel * aChannel, nsISupports *ctxt, nsresult aStatus, const PRUnichar *aMsg)
+{
+  return NS_OK;
+}
+
 NS_IMETHODIMP
 nsImapMailFolder::OnStartRunningUrl(nsIURI *aUrl)
 {
diff --git a/mailnews/imap/src/nsImapMailFolder.h b/mailnews/imap/src/nsImapMailFolder.h
index 832a7213225f..325e989cc868 100644
--- a/mailnews/imap/src/nsImapMailFolder.h
+++ b/mailnews/imap/src/nsImapMailFolder.h
@@ -44,7 +44,7 @@
 #include "nsIMsgImapMailFolder.h"
 #include "nsIImapMailFolderSink.h"
 #include "nsIImapServerSink.h"
-
+#include "nsIStreamListener.h"
 class nsImapMoveCoalescer;
 
 
@@ -99,7 +99,8 @@ class nsImapMailFolder : public nsMsgDBFolder,
                          public nsIImapExtensionSink,
                          public nsIImapMiscellaneousSink,
                          public nsICopyMessageListener,
-						 public nsIMsgFilterHitNotify
+						             public nsIMsgFilterHitNotify,
+                         public nsIStreamListener
 {
 public:
 	nsImapMailFolder();
@@ -195,6 +196,9 @@ public:
     //nsICopyMessageListener
 	NS_DECL_NSICOPYMESSAGELISTENER
 
+	NS_DECL_NSISTREAMOBSERVER
+
+	NS_DECL_NSISTREAMLISTENER
     // nsIUrlListener methods
 	NS_IMETHOD OnStartRunningUrl(nsIURI * aUrl);
 	NS_IMETHOD OnStopRunningUrl(nsIURI * aUrl, nsresult aExitCode);
diff --git a/mailnews/imap/src/nsImapService.cpp b/mailnews/imap/src/nsImapService.cpp
index 832e92f5d354..738db6a176d3 100644
--- a/mailnews/imap/src/nsImapService.cpp
+++ b/mailnews/imap/src/nsImapService.cpp
@@ -878,7 +878,7 @@ NS_IMETHODIMP nsImapService::SaveMessageToDisk(const char *aMessageURI,
         msgUrl->SetAddDummyEnvelope(aAddDummyEnvelope);
         msgUrl->SetCanonicalLineEnding(canonicalLineEnding);
 
-        return FetchMessage(imapUrl, nsIImapUrl::nsImapSaveMessageToDisk, folder, imapMessageSink, aMsgWindow, aURL, imapMessageSink, msgKey, PR_TRUE);
+        return FetchMessage(imapUrl, nsIImapUrl::nsImapSaveMessageToDisk, folder, imapMessageSink, aMsgWindow, aURL, nsnull, msgKey, PR_TRUE);
     }
 
 	return rv;
@@ -3149,3 +3149,29 @@ nsImapService::UnsubscribeFolder(nsIEventQueue* eventQueue,
     }
     return rv;
 }
+
+NS_IMETHODIMP
+nsImapService::DownloadMessagesForOffline(const char *messageIds, nsIMsgFolder *aFolder, nsIMsgWindow *aMsgWindow)
+{
+  NS_ENSURE_ARG_POINTER(aFolder);
+  NS_ENSURE_ARG_POINTER(messageIds);
+  
+  nsCOMPtr<nsIImapUrl> imapUrl;
+  nsCAutoString urlSpec;
+  nsresult rv;
+  PRUnichar hierarchySeparator = GetHierarchyDelimiter(aFolder);
+  rv = CreateStartOfImapUrl(nsnull, getter_AddRefs(imapUrl), aFolder, nsnull,
+                            urlSpec, hierarchySeparator);
+  if (NS_SUCCEEDED(rv) && imapUrl)
+  {
+      if (NS_SUCCEEDED(rv))
+      {
+        // need to pass in stream listener in order to get the channel created correctly
+        nsCOMPtr<nsIImapMessageSink> imapMessageSink(do_QueryInterface(aFolder, &rv));
+        nsCOMPtr<nsIStreamListener> folderStreamListener(do_QueryInterface(aFolder, &rv));
+        rv = FetchMessage(imapUrl, nsImapUrl::nsImapMsgFetch,aFolder, imapMessageSink, 
+                            aMsgWindow, nsnull, folderStreamListener, messageIds, PR_TRUE);
+      }
+  }
+  return rv;
+}