Undeliverable email - with unknow domain names

Our email server is getting hit with many emails that are getting returned undeliveralble.  Example:

 Subject:      Delivery Status Notification (Failure)
      Sent:      6/27/2006 3:01 PM
The following recipient(s) could not be reached:
      nasszabo@fnbmarengo.com on 6/27/2006 3:01 PM
            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.
            <dc-exchange.fnbmarengo.com #5.1.1>
---------------------------------------------------------------------------
The following recipient(s) could not be reached:
      zephyufea@fcacorp.com on 6/19/2006 1:22 AM
            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.
            <mail.fcacorp.com #5.1.1>
--------------------------------------------------------------------------
Our domain is xxxxxxxx@delkin.com, why are all these coming in that are not even close to our domain name?  Is someone trying to relay?
Scott
Scott JohnstonSystems ConsultantAsked:
Who is Participating?

Improve company productivity with a Business Account.Sign Up

x
 
SembeeConnect With a Mentor Commented:
Could be a spoofed message attack - where messages are being sent with your domain name in the From: line.
Could be an NDR attack - where messages are sent to your domain with invalid information on purpose, to bounce the message to the real target.

If the first, not a lot you can do about it.
If the second, then you can setup some kind of recipient filtering. What you can do depends on the version of Exchange.

Also don't forget that spammers make heavy use of BCC.

Simon.
0
Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

All Courses

From novice to tech pro — start learning today.