Adding a new string resource for an alert, bug 28908, r=ducarroz.

mailnews/compose/resources/locale/en-US/composeMsgs.properties

@@ -170,6 +170,9 @@ noIdentities=You don't have any email identities yet.  Create one with the Accou
 ## @name NS_MSG_ATTACHMENT_TYPE_MISMATCH
 12552=<Image Signature Omitted>
 
+## @name NS_MSG_MULTILINGUAL_SEND
+12553=Message may not be sent correctly because it contains character(s) out of charset range. Send anyway or cancel to back to compose?
+
 ## Strings use for the save message dialog shown when the user close a message compose window
 saveDlogTitle=Save Message
 saveDlogMessage=Message has not been Sent. Do you want to save the message in the Drafts Folder?

mailnews/compose/src/nsMsgComposeStringBundle.h

@@ -100,4 +100,6 @@ private:
 #define NS_MSG_POSTING_MESSAGE                      NS_MSG_GENERATE_SUCCESS(12551)
 #define NS_MSG_ATTACHMENT_TYPE_MISMATCH             NS_MSG_GENERATE_FAILURE(12552)
 
+#define NS_MSG_MULTILINGUAL_SEND                    NS_MSG_GENERATE_SUCCESS(12553)
+
 #endif /* _nsMsgComposeStringBundle_H_ */