>the SMTP process on Krypton rejected it
>with:
>    553 header line too long
>My guess is that Krypton can't handle the long RFC822 header lines
>that are now available.  LMail translated this error report into an
>Error Code 3 (permanent delivery failure).  LISTSERV interprets Error
>Code 3 to mean unsubscribe this userid.
 
Here is the official meaning of 553 from RFC821:
 
          553 Requested action not taken: mailbox name not allowed
             [E.g., mailbox syntax incorrect]
 
This code  is to be  used only  after RCPT TO:  or VRFY, when  an invalid
mailbox is specified.  The correct code for an error  of the type "header
too long" after the DATA instruction is  554, so this is probably a typo.
LMail translates 554 to a soft error and 553 to a hard one.
 
This being said,  deleting the user was  the correct thing to  do. If his
mail  system can't  handle 'Received:'  fields of  two lines,  you aren't
going to get much mail to his mailbox anyway.
 
  Eric