RE: Relaying question

  • From: "Thomas W Shinder" <tshinder@xxxxxxxxxxxxxxxxxx>
  • To: "[ExchangeList]" <exchangelist@xxxxxxxxxxxxx>
  • Date: Fri, 26 Sep 2003 08:50:22 -0500

Hi Chris,
Yes. If you don't allow relay, then the server will not relay. You can
also do other things like prevent the machine from resolving Internet
host names (just for fun).
Thomas W Shinder <>  
ISA Server and Beyond:
Configuring ISA Server:


        -----Original Message-----
        From: Allen, Chris [mailto:CAllen@xxxxxxxxxxxxxxxx] 
        Sent: Friday, September 26, 2003 8:34 AM
        To: [ExchangeList]
        Subject: [exchangelist] Relaying question


        Per SpamCop and SpamHaus, "Spammers are taking advantage of weak
passwords on systems using smtp/auth and brute force finding
name/password combinations that work and then sending spam thru these
servers. There are various characteristic footprints for this and one of
them is the use of a "from" address of the format bluestallnn@some legit
ISP and the "nn" iterates in each successive spam.




        bluestelluf@xxxxxxxxx "


        My question is this, if I uncheck "Allow all computers which
successfully authenticate to relay, regardless of the list above", will
this effectively stop brute force attacks on weak passwords as far as
exchange is concerned and what will this break?


        I am also taking measure by blocking their entire block of IPs.
The ranges are as follows:


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