> To  clarify  what  the  context  of  the  statement.  This was about
> Exchange.  There  is a "catch-all" script for Exchange which I guess
> is similar to our nobody alias, but on a server wide scale.

It's not a script. The (stupid) Exchange default setting -- and in old
versions  of  Exchange,  the  only  setting  -- is to allow mail to be
accepted  for  any recipient at a serviced domain. After the SMTP side
accepts  all messages, bounces are then generated, by the mailbox side
of the engine, for invalid users.

This  behavior  used  to  be  a  mandate with Exchange unless you used
3rd-party   envelope-rejection   software,  and  Microsoft  made  some
half-arsed  rationalizations  of  it,  and  that  in turn led a lot of
uneducated  admins to learn the wrong approach. In Exchange 2003, they
finally made it possible to reject invalid recipients at the envelope.
But  admins  schooled  in  the  old,  stupid  ways still think this is
somehow wrong -- they don't realize how obsolete their thinking is.

> He  says  that  a  mail  server  should never reject a connection as
> invalid.

Then he doesn't know anything about spam past, oh, 1996?

> If  I  sent  a message to an invalid address the server should never
> let  anyone know if the address is valid or not.

As  Len  has  often  said,  and  I have always agreed, knowing a valid
address should be no predictor of one's ability to get spam or viruses
delivered to that address.

> So  in  the context of the discussion Imail does reveal non-existant
> email addresses which he claims should never be done.

Yup,  hogwash.  You  should  be  so  lucky  as to have IMail rejecting
unknown recipients at the envelope. In a gateway config, IMail accepts
all  recipients at serviced domains, and that's a tremendous liability
--  and  that's  why  I  created the exchange2aliases and ldap2aliases
scripts  in my sig, to *combat* this bad design. And apparently you've
still got ignoramuses throwing FUD out there defending the bad design.

--Sandy



------------------------------------
Sanford Whiteman, Chief Technologist
Broadleaf Systems, a division of
Cypress Integrated Systems, Inc.
e-mail: [EMAIL PROTECTED]

SpamAssassin plugs into Declude!
  http://www.imprimia.com/products/software/freeutils/SPAMC32/download/release/

Defuse Dictionary Attacks: Turn Exchange or IMail mailboxes into IMail Aliases!
  
http://www.imprimia.com/products/software/freeutils/exchange2aliases/download/release/
  
http://www.imprimia.com/products/software/freeutils/ldap2aliases/download/release/

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