diff --git a/mailnews/base/public/nsIMsgFolderCompactor.idl b/mailnews/base/public/nsIMsgFolderCompactor.idl
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+++ b/mailnews/base/public/nsIMsgFolderCompactor.idl
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+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ *
+ * The contents of this file are subject to the Netscape Public
+ * License Version 1.1 (the "License"); you may not use this file
+ * except in compliance with the License. You may obtain a copy of
+ * the License at http://www.mozilla.org/NPL/
+ *
+ * Software distributed under the License is distributed on an "AS
+ * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
+ * implied. See the License for the specific language governing
+ * rights and limitations under the License.
+ *
+ * The Original Code is mozilla.org code.
+ *
+ * The Initial Developer of the Original Code is Netscape
+ * Communications Corporation.  Portions created by Netscape are
+ * Copyright (C) 2001 Netscape Communications Corporation. All
+ * Rights Reserved.
+ *
+ * Contributor(s): 
+ */
+
+#include "nsISupports.idl"
+
+interface nsIMsgFolder;
+interface nsIMsgDatabase;
+interface nsIFileSpec;
+
+
+[scriptable, uuid(2af7d7a2-e5b6-11d4-a5b7-0060b0fc04b7)]
+
+/*  Use this for any object that wants to handle compacting folders */
+
+interface nsIMsgFolderCompactor :  nsISupports
+{
+  void Init(in nsIMsgFolder folder, in string baseMsgUri, in nsIMsgDatabase db,
+                           in nsIFileSpec pathSpec);
+  // we probably want to add the ability to set an enumerator to determine which
+  // messages to copy over in the compaction process.
+  void StartCompacting();
+  void FinishCompact();
+};