COMMAND

    smtpsvc.dll

SYSTEMS AFFECTED

    Windows NT

PROBLEM

    Nelson Bunker found following.  This was tested with IIS4.0 option
    pack  SMTP  service  (post  SP4)  for  outgoing mail.  You may get
    several complaints  regarding an  issue with  trying to  send mail
    destined for servers running "Qmail".   It appears that the  Qmail
    shuts down the  connection with out  giving an error  message.  In
    return the  IIS Server  acts as  if nothing  happened and tries to
    re-open the connection.  It would appear that Microsoft has  given
    away a great DOS attack for QMail...

SOLUTION

    If you find this problem happening to you there are fixes on  both
    product sides.  Qmail has  provided a patch for stray  line feeds.
    It is available through there site.  You will have to ask a  qmail
    expert for more info.  Microsoft has patched their smtpsvc.dll  to
    version v5.5.1877.18.  It can be obtained through Microsoft if you
    know what to ask for.