diff --git a/mailnews/compose/macbuild/msgComposeIDL.mcp b/mailnews/compose/macbuild/msgComposeIDL.mcp
index e12f23d761a0..ec30e9719db4 100644
Binary files a/mailnews/compose/macbuild/msgComposeIDL.mcp and b/mailnews/compose/macbuild/msgComposeIDL.mcp differ
diff --git a/mailnews/compose/public/MANIFEST_IDL b/mailnews/compose/public/MANIFEST_IDL
index 4c55359cb72f..be619dc63215 100644
--- a/mailnews/compose/public/MANIFEST_IDL
+++ b/mailnews/compose/public/MANIFEST_IDL
@@ -23,4 +23,4 @@
 nsISmtpServer.idl
 nsISmtpUrl.idl
 nsISmtpService.idl
-
+nsIMsgComposeSecure.idl
diff --git a/mailnews/compose/public/Makefile.in b/mailnews/compose/public/Makefile.in
index b33fdc98e824..f146072c810e 100644
--- a/mailnews/compose/public/Makefile.in
+++ b/mailnews/compose/public/Makefile.in
@@ -50,6 +50,7 @@ XPIDLSRCS	= \
 		nsISmtpUrl.idl \
 		nsISmtpService.idl \
 		nsIURLFetcher.idl \
+		nsIMsgComposeSecure.idl \
 		$(NULL)
 
 include $(topsrcdir)/config/rules.mk
diff --git a/mailnews/compose/public/makefile.win b/mailnews/compose/public/makefile.win
index 16c5eeffd5e1..9f89ca096be6 100644
--- a/mailnews/compose/public/makefile.win
+++ b/mailnews/compose/public/makefile.win
@@ -27,20 +27,21 @@ XPIDLSRCS =										            \
 				.\nsIMsgComposeProgressParams.idl	\
 				.\nsIMsgComposeParams.idl		      \
 				.\nsIMsgComposeService.idl		    \
-				.\nsIMsgCompose.idl				        \
+				.\nsIMsgCompose.idl	        \
 				.\nsIMsgCompFields.idl			      \
-				.\nsIMsgQuote.idl				          \
+				.\nsIMsgQuote.idl		          \
 				.\nsIMsgSendListener.idl		      \
 				.\nsIMsgSendLaterListener.idl	    \
-				.\nsIMsgSend.idl				          \
-				.\nsIMsgSendLater.idl			        \
+				.\nsIMsgSend.idl	          \
+				.\nsIMsgSendLater.idl       \
 				.\nsIMsgSendReport.idl			      \
 				.\nsIMsgRecipientArray.idl		    \
-				.\nsIMsgDraft.idl				          \
-				.\nsISmtpServer.idl				        \
-				.\nsISmtpUrl.idl				          \
-				.\nsISmtpService.idl			        \
-				.\nsIURLFetcher.idl			          \
+				.\nsIMsgDraft.idl          \
+				.\nsISmtpServer.idl	        \
+				.\nsISmtpUrl.idl          \
+				.\nsISmtpService.idl        \
+				.\nsIURLFetcher.idl          \
+				.\nsIMsgComposeSecure.idl      \
 				$(NULL)
 
 ################################################################################
diff --git a/mailnews/compose/public/nsIMsgComposeSecure.idl b/mailnews/compose/public/nsIMsgComposeSecure.idl
new file mode 100644
index 000000000000..46c80d4284de
--- /dev/null
+++ b/mailnews/compose/public/nsIMsgComposeSecure.idl
@@ -0,0 +1,47 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ *
+ * 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) 1998 Netscape Communications Corporation. All
+ * Rights Reserved.
+ *
+ * Contributor(s): 
+ *       David Drinan <ddrinan@netscape.com>
+ *       Scott MacGregor <mscott@netscape.com> 
+ */
+
+#include "nsISupports.idl"
+
+interface nsIMsgCompFields;
+interface nsIMsgIdentity;
+
+%{C++
+class nsOutputFileStream;
+%}
+
+[ptr] native nsOutputFileStream(nsOutputFileStream);
+
+/* Security interface */
+[noscript, uuid(ed899511-b473-4a93-ba02-d8cb90d58e1c)]
+interface nsIMsgComposeSecure : nsISupports 
+{
+    // requiresCryptoEncapsulation --> returns true if the current message send requires us to go through
+	// some encryption work. In the case of false, you can disregard the compose secure object.
+    boolean requiresCryptoEncapsulation(in nsIMsgIdentity aIdentity, in nsIMsgCompFields aCompFields);
+
+	void beginCryptoEncapsulation(in nsOutputFileStream aStream, in string aRecipients, in nsIMsgCompFields aCompFields, in nsIMsgIdentity aIdentity, in boolean aIsDraft);
+	void finishCryptoEncapsulation(in boolean aAbort);
+	void mimeCryptoWriteBlock(in string aBuf, in long aLen);
+};