diff --git a/mailnews/imap/public/nsIImapHeaderXferInfo.idl b/mailnews/imap/public/nsIImapHeaderXferInfo.idl
new file mode 100644
index 00000000000..2b6ab0bb818
--- /dev/null
+++ b/mailnews/imap/public/nsIImapHeaderXferInfo.idl
@@ -0,0 +1,55 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* ***** BEGIN LICENSE BLOCK *****
+ * Version: NPL 1.1/GPL 2.0/LGPL 2.1
+ *
+ * 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 the Initial Developer are Copyright (C) 2002
+ * the Initial Developer. All Rights Reserved.
+ *
+ * Contributor(s):
+ *
+ * Alternatively, the contents of this file may be used under the terms of
+ * either the GNU General Public License Version 2 or later (the "GPL"), or 
+ * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
+ * in which case the provisions of the GPL or the LGPL are applicable instead
+ * of those above. If you wish to allow use of your version of this file only
+ * under the terms of either the GPL or the LGPL, and not to allow others to
+ * use your version of this file under the terms of the NPL, indicate your
+ * decision by deleting the provisions above and replace them with the notice
+ * and other provisions required by the GPL or the LGPL. If you do not delete
+ * the provisions above, a recipient may use your version of this file under
+ * the terms of any one of the NPL, the GPL or the LGPL.
+ *
+ * ***** END LICENSE BLOCK ***** */
+
+#include "nsISupports.idl"
+#include "MailNewsTypes2.idl"
+
+[scriptable, uuid(38f8f784-b092-11d6-ba4b-00108335942a)]
+interface nsIImapHeaderInfo : nsISupports {
+    readonly attribute nsMsgKey  msgUid;
+    attribute long      msgSize;
+    [noscript] void getMsgHdrs ([shared] out string aMsgHdrs); // this doesn't copy the msgHdrs
+    void cacheLine(in string line, in unsigned long uid);
+    void resetCache();
+};
+
+[scriptable, uuid(f0842eda-af29-4ecd-82e1-fba91bd65d66)]
+interface nsIImapHeaderXferInfo : nsISupports {
+  readonly attribute unsigned long numHeaders;
+  nsIImapHeaderInfo  getHeader(in long hdrIndex);
+};
+