I like the wording of the subject ....
How about the  following: assuming that programmers try  to make messages
"nice"  and original  while preserving  a minimum  amount of  information
they'd refrain from wordings a human  being could possibly use. Now if we
- the  humans - would  start a  subject (and maybe  the text too)  - with
something like "uh, hum" or "ah, err" or "well ..." then it'd be easy for
LISTSERV to sort out the non-humans (and therefore the error messages).
Of course this wouldn't work forever.  I'd expect subjects like: "Well, I
hate to say it, but your mailing just didn't make it" to turn up after at
most two years ...
 
.......
>Reply-To:     SMTP MAILER <[log in to unmask]>
>Sender:       "SAS(r) Discussion" <[log in to unmask]>
>From:         SMTP MAILER <[log in to unmask]>
>Subject:      Mail Delivery Problem
>Comments: To: sas-l <[log in to unmask]>
>To:           Christian Reichetzeder <[log in to unmask]>
>
> ----Reason for mail failure follows----
>Sending mail to recipient(s) jlorman :
>  Couldn't make final delivery.
>
>%MAIL-E-OPENOUT, error opening !AS as output
 
Christian
P.S.: Also note: "Couldn't make final  delivery." ... watch out for poets
      as programmers ;-)