I "love" (not) messages like these: the mail host (SENDMAIL) says that
it (self) is unavailable for deliverying the mail, but has no problem
bouncing it back ... all from the same host site

------------------------------ Message in error
-------------------------------
Received: from PSUVM (NJE origin SMTP@PSUVM) by PSUVM.PSU.EDU (LMail
          V1.2c/1.8c) with BSMTP id 0320; Thu, 12 Feb 1998 14:51:47
-0500
Received: from falcon.tamucc.edu (165.95.8.16,2526) by PSUVM.PSU.EDU
   (IBM VM SMTP V2R2) with TCP; Thu, 12 Feb 98 14:51:46 EST
Received: by falcon.tamucc.edu; id AA14489; Thu, 12 Feb 1998 13:53:09
-0600
Date: Thu, 12 Feb 1998 13:53:09 -0600
From: Mail Delivery Subsystem <[log in to unmask]>
Subject: Returned mail: Service unavailable
Message-Id: <[log in to unmask]>
To: [log in to unmask]

   ----- Transcript of session follows -----
554 <[log in to unmask]>... Service unavailable

   ----- Unsent message follows -----