Is my Exchange Server server an open relay?

Hi Experts,

Just got an "undeliverable" error message in my inbox, although I've never sent an email to (or even heard of) this person before. I know, it may be spam "pretending" to be an undeliverable message, but the "envelope icon" associated with each message as apart of Outlook changed to match the conventional "undeliverable" icon. The error is said to be coming from the "system administrator".

Here is the message:


Your message

  To:      max@brentwoodprinting.com
  Subject: RE: January 71% OFF
  Sent:    Sat, 19 Jan 2008 18:29:40 -0800

did not reach the following recipient(s):

max@brentwoodprinting.com on Sat, 19 Jan 2008 18:29:41 -0800
    The e-mail account does not exist at the organization this message
was sent to.  Check the e-mail address, or contact the recipient
directly to find out the correct address.
    <dibadi.net #5.1.1 smtp;550 5.1.1 RESOLVER.ADR.RecipNotFound; not
found>
ü
Reporting-MTA: dns; EXCHANGE01.OURDOMAINGOESHERE.com

Final-Recipient: RFC822; max@brentwoodprinting.com
Action: failed
Status: 5.1.1
X-Supplementary-Info: <dibadi.net #5.1.1 smtp;550 5.1.1 RESOLVER.ADR.RecipNotFound; not found>
X-Display-Name: max@brentwoodprinting.com
ü
Date: Sat, 19 Jan 2008 18:29:40 -0800
To: <max@brentwoodprinting.com>
Conversation: January 71% OFF
Subject: RE: January 71% OFF



What is even more convincing is that in the message above, our server is mentioned as the "Reporting-MTA" (I replaced our actual domain with: "EXCHANGE01.OURDOMAINGOESHERE.com" for, ironically enough, spam reasons)

So if there is a legitimate problem, then what would be the first step in fixing it?

Thanks for your assistance,
MaxStart Free Trial