Open Relay

[Chris McKeever]

Exchange 5.5 sp4
Windows NT SP6

I have turned on require SMTP to authenticate to prevent open relay,
seems to be working well considering the amount of users that are
bitching because they need to change thier set-ups.

I have run a relay check utility at:

http://www.paladincorp.com.au/cgi-bin/spamlart.cgi?DESTINATION=mail.prupref.com

and I get a lot of vulnerabilities, does anyone know how to remedy
these:

250 OK - mail from <postm...@mail.prupref.com>
rcpt to: <"spam...@paladincorp.com.au"@mail.prupref.com>
250 OK - Recipient <"spam...@paladincorp.com.au"@mail.prupref.com>
** FAILURE / Potentital Vulnerability **

rcpt to: <spamtest%paladinco...@mail.prupref.com>
250 OK - Recipient <spamtest%paladinco...@mail.prupref.com>
** FAILURE / Potentital Vulnerability **

rcpt to: <paladincorp.com.au!spamtest>
250 OK - Recipient <paladincorp.com.au!spamtest>
** FAILURE / Potentital Vulnerability **

rcpt to: <paladincorp.com.au!spam...@mail.prupref.com>
250 OK - Recipient <paladincorp.com.au!spam...@mail.prupref.com>
** FAILURE / Potentital Vulnerability **

Thanks

[Andy David [MVP]]

Take a gander at this:
http://support.microsoft.com/default.aspx?scid=kb%3Ben-us%3B196626

"Chris McKeever" <cgmck...@yahoo.com> wrote in message
news:1a78c305.03022...@posting.google.com...

[Ed Crowley [MVP]]

The question is, "Was that message relayed?" Just because the e-mail system
accepted it doesn't mean it relayed it.
--
Ed Crowley
MVP - Exchange
"Protecting the world from PSTs and brick backups!"

"Chris McKeever" <cgmck...@yahoo.com> wrote in message
news:1a78c305.03022...@posting.google.com...

[John Karr]

What the "250 OK" is telling you is that you are still relaying. The
correct error message should read "550 Relaying Prohibited"

John Karr

"Chris McKeever" <cgmck...@yahoo.com> wrote in message
news:1a78c305.03022...@posting.google.com...

[Ed Crowley [MVP]]

Not necessarily. It tells you that the message was accepted for delivery.
Exchange will accept messages it thinks are for local delivery, but not
relay them. What really matters is not the code you get, but whether or not
the messages are actually relayed. Note that the alarms say "POTENTIAL
vulnerability." It is up to the engineer to determine whether the potential
is real.

--
Ed Crowley
MVP - Exchange
"Protecting the world from PSTs and brick backups!"

"John Karr" <jk...@delmarvawebdesigns.com> wrote in message
news:#ZX24tC3...@TK2MSFTNGP09.phx.gbl...

[John Karr]

You are correct. I don't know where my head was. I found that www.ordb.org
does a pretty good test for an open relay as well as provide links to other
sites/lists for Open Relays.

John

"Ed Crowley [MVP]" <curs...@pacbellnospam.net> wrote in message
news:en5reJD3...@TK2MSFTNGP10.phx.gbl...