Hello all, I have an Exchange 2003 org that forwards mail to a smart relay (IIS 6 Server) and quite often I see e-mails that are 0 KB in size. If I open one of those messages in the queue, it states: From: Sender Unspecified To: None Subject: (No Subject) Body of e-mail is blank... They generally appear for only a few seconds before being deleted, but I want to know where they are coming from. And yes, the relay is LOCKED down to only certain approved internal IP's. What could be causing them? Thanks for your thoughts.