diff --git a/mozilla/mailnews/base/public/nsIMsgAccountManager.idl b/mozilla/mailnews/base/public/nsIMsgAccountManager.idl
index 4fa47e10e38..7a8e5420905 100644
--- a/mozilla/mailnews/base/public/nsIMsgAccountManager.idl
+++ b/mozilla/mailnews/base/public/nsIMsgAccountManager.idl
@@ -121,6 +121,7 @@ interface nsIMsgAccountManager : nsISupports {
 
   void WriteToFolderCache(in nsIMsgFolderCache folderCache);
 
+  void CloseCachedConnections();
   /* search for 4.x mailnews prefs, and migrate to 5.0 prefs */
   void UpgradePrefs();
 };
diff --git a/mozilla/mailnews/base/public/nsIMsgIncomingServer.idl b/mozilla/mailnews/base/public/nsIMsgIncomingServer.idl
index e448fc6eb49..3ba4443e559 100644
--- a/mozilla/mailnews/base/public/nsIMsgIncomingServer.idl
+++ b/mozilla/mailnews/base/public/nsIMsgIncomingServer.idl
@@ -83,6 +83,9 @@ interface nsIMsgIncomingServer : nsISupports {
 
   void WriteToFolderCache(in nsIMsgFolderCache folderCache);
 
+  // either we're going offline, or shutting down.
+  void CloseCachedConnections();
+
   /* access to generic attributes */
   boolean getBoolValue(in string attr);
   void setBoolValue(in string attr, in boolean value);
diff --git a/mozilla/mailnews/base/src/nsMsgAccountManager.cpp b/mozilla/mailnews/base/src/nsMsgAccountManager.cpp
index 4f2234ea365..b47c36f4c9c 100644
--- a/mozilla/mailnews/base/src/nsMsgAccountManager.cpp
+++ b/mozilla/mailnews/base/src/nsMsgAccountManager.cpp
@@ -398,6 +398,7 @@ private:
 
   // write out the server's cache through the given folder cache
   static PRBool writeFolderCache(nsHashKey *aKey, void *aData, void *closure);
+  static PRBool closeCachedConnections(nsHashKey *aKey, void *aData, void *closure);
 
   // methods for migration / upgrading
   nsresult MigrateIdentity(nsIMsgIdentity *identity);
@@ -474,7 +475,7 @@ nsMsgAccountManager::nsMsgAccountManager() :
 
 nsMsgAccountManager::~nsMsgAccountManager()
 {
-  
+  CloseCachedConnections();
   if (m_prefs) nsServiceManager::ReleaseService(kPrefServiceCID, m_prefs);
   UnloadAccounts();
   NS_IF_RELEASE(m_accounts);
@@ -842,6 +843,16 @@ PRBool nsMsgAccountManager::writeFolderCache(nsHashKey *aKey, void *aData,
 	return PR_TRUE;
 }
 
+// enumaration for closing cached connections.
+PRBool nsMsgAccountManager::closeCachedConnections(nsHashKey *aKey, void *aData,
+                                             void *closure)
+{
+    nsIMsgIncomingServer *server = (nsIMsgIncomingServer*)aData;
+
+	server->CloseCachedConnections();
+	return PR_TRUE;
+}
+
 
 /* readonly attribute nsISupportsArray accounts; */
 NS_IMETHODIMP
@@ -1094,6 +1105,12 @@ nsMsgAccountManager::UnloadAccounts()
   return NS_OK;
 }
 
+NS_IMETHODIMP
+nsMsgAccountManager::CloseCachedConnections()
+{
+	m_incomingServers.Enumerate(closeCachedConnections, nsnull);
+	return NS_OK;
+}
 
 NS_IMETHODIMP
 nsMsgAccountManager::WriteToFolderCache(nsIMsgFolderCache *folderCache)
diff --git a/mozilla/mailnews/base/src/nsMsgMailSession.cpp b/mozilla/mailnews/base/src/nsMsgMailSession.cpp
index e2efbd3b66c..5fbb25c5fcd 100644
--- a/mozilla/mailnews/base/src/nsMsgMailSession.cpp
+++ b/mozilla/mailnews/base/src/nsMsgMailSession.cpp
@@ -53,6 +53,7 @@ nsMsgMailSession::~nsMsgMailSession()
   {
 //	  if (m_msgFolderCache)
 //		m_accountManager->WriteToFolderCache(m_msgFolderCache);
+	  m_accountManager->CloseCachedConnections();
 	  m_accountManager->UnloadAccounts();
   }
 
diff --git a/mozilla/mailnews/base/util/nsMsgIncomingServer.cpp b/mozilla/mailnews/base/util/nsMsgIncomingServer.cpp
index 81f9db172fd..2a271675441 100644
--- a/mozilla/mailnews/base/util/nsMsgIncomingServer.cpp
+++ b/mozilla/mailnews/base/util/nsMsgIncomingServer.cpp
@@ -123,6 +123,14 @@ NS_IMETHODIMP nsMsgIncomingServer::WriteToFolderCache(nsIMsgFolderCache *folderC
 	return rv;
 }
 
+NS_IMETHODIMP
+nsMsgIncomingServer::CloseCachedConnections()
+{
+	// derived class should override if they cache connections.
+	return NS_OK;
+}
+
+
 NS_IMETHODIMP
 nsMsgIncomingServer::GetServerURI(char **)
 {
diff --git a/mozilla/mailnews/imap/src/nsImapIncomingServer.cpp b/mozilla/mailnews/imap/src/nsImapIncomingServer.cpp
index c5c31ab4dc8..94711e64f0b 100644
--- a/mozilla/mailnews/imap/src/nsImapIncomingServer.cpp
+++ b/mozilla/mailnews/imap/src/nsImapIncomingServer.cpp
@@ -74,6 +74,7 @@ public:
 	NS_DECL_NSIIMAPSERVERSINK
     
 	NS_IMETHOD PerformBiff();
+	NS_IMETHOD CloseCachedConnections();
 
 protected:
 	nsresult GetFolder(const char* name, nsIMsgFolder** pFolder);
@@ -524,6 +525,30 @@ NS_IMETHODIMP nsImapIncomingServer::PerformBiff()
 	return rv;
 }
     
+NS_IMETHODIMP
+nsImapIncomingServer::CloseCachedConnections()
+{
+
+	nsCOMPtr<nsIImapProtocol> connection;
+    PR_CEnterMonitor(this);
+
+	// iterate through the connection cache closing open connections.
+	PRUint32 cnt;
+    nsCOMPtr<nsISupports> aSupport;
+
+    nsresult rv = m_connectionCache->Count(&cnt);
+    if (NS_FAILED(rv)) return rv;
+    for (PRUint32 i = 0; i < cnt; i++) 
+	{
+        aSupport = getter_AddRefs(m_connectionCache->ElementAt(i));
+        connection = do_QueryInterface(aSupport);
+		if (connection)
+			rv = connection->TellThreadToDie(PR_TRUE);
+	}
+    
+    PR_CExitMonitor(this);
+	return rv;
+}
 
 nsresult NS_NewImapIncomingServer(const nsIID& iid,
                                   void **result)
@@ -1323,7 +1348,6 @@ NS_IMETHODIMP nsImapIncomingServer::PseudoInterruptMsgLoad(nsIMsgFolder *aFolder
 	PRBool canRunUrl = PR_FALSE;
     PRBool hasToWait = PR_FALSE;
 	nsCOMPtr<nsIImapProtocol> connection;
-    nsCOMPtr<nsIImapProtocol> freeConnection;
     PRBool isBusy = PR_FALSE;
     PRBool isInboxConnection = PR_FALSE;