Mail Server DNS Name Invalid

Why You Are Here

The most probable reason that your reading this page is that you have received an error message whilst trying to send us email.

The error message contains a URL of this page.

How Your Email Message Was Blocked

We have chosen to implement a policy to deny access to our email servers from Mail Servers that do not have a valid DNS name.

As a result our email servers will block email messages from these IP addresses.

Why Your Email Message Was Blocked

We have opted for this policy in response to the increase of SPAM and email messages containing viruses being sent to us.

From our analysis of these unwanted emails, we have determined that a large number of emails are originating from IP addresses without valid DNS names.

So in an effort to reduce wasted resources and time we have decided to implement a policy of refusing connection to our mail servers from these IP addresses.

It is our belief that a server that is sending email should have a DNS name, if it does not, we assume it is mis-configured or a hijacked computer (zombie computer).

What Is A DNS Name?

An IP address can have a DNS (Domain Name System) name (or internet address) associated with it.

These addresses make it easier for users to understand locations on the internet.


Have your system administrator put a DNS name on the IP of the computer host sending the email.

If that is not available, move to an ISP with a more responsible attitude.

If You Believe You Are Not At Fault

Send a message to the Postmaster via our Feedback page.

Please include details of where you are trying to send your email from.

Please note you are very likely have to change your email address (or internet provider), as the feedback program requires confirmation of your email address using the same spam rejection mechanisms that landed you here in the first place.