Much of the standard error handling that works is on the basis of
"standard practices" rather than standards.  In essence the alaska system
was forging mail by using that From line when it should probably have
included the original message within it's own set of RFC822 headers.
 
   However, RFC1123 (Host Requirements) is pretty clear of sending
errors to the MAIL FROM address and not letting you off the hook just
because SMTP had accepted the message:
 
         When the receiver-SMTP makes "final delivery" of a message,
         then it MUST pass the MAIL FROM: address from the SMTP envelope
         with the message, for use if an error notification message must
         be sent later (see Section 5.3.3).  There is an analogous
         requirement when gatewaying from the Internet into a different
         mail environment; see Section 5.3.7.
 
         DISCUSSION:
              Note that the final reply to the DATA command depends only
              upon the successful transfer and storage of the message.
              Any problem with the destination address(es) must either
              (1) have been reported in an SMTP error reply to the RCPT
              command(s), or (2) be reported in a later error message
              mailed to the originator.
 
         IMPLEMENTATION:
              The MAIL FROM: information may be passed as a parameter or
              in a Return-Path: line inserted at the beginning of the
              message.
 
   Marty