Step #1 - Use only MX Guarddog's Servers

We provide every domain with a set of three MX servers. These servers provide your domain's email with geographic redundancy, maximized for high availability.

Use only servers assigned to you. Leaving additional servers in your MX record list will allow spammers to send their spam direct to your server. In a perfect world email servers should try the first server and move down the list until it finds an operational server to accept your mail.

Unfortunately, in the real world spammers will attempt to deliver their spam to all MX servers (or the server with the lowest priority) in an attempt to bypass spam protection.

Step #2 - Harden Your Server

At this point, we know to use only MX Guarddog servers. That is not enough to stop some spammers, with more spam organizations using a technique called a direct delivery attack. Spammers simply ignore your MX records, attempting to deliver their junk direct to your server by trying common server names such as mail.example.com or the IP address of your website.

To stop these spammers you must harden your email server, forcing all mail for your domain to pass through the MX Guarddog servers. For tips about protecting your server check our blog posting about direct delivery attacks.

Step #3 - Country Blocking

Most organizations receive the bulk of their mail from their home country. If you are based in Germany most of your legitimate mail will come from Germany, if you are based in Canada most of your mail will come from Canada.

If you do not communicate with people from Algeria, Mexico or Namibia you can block those countries and greatly reduce the spam that reaches you. The more countries you blacklist the less spam you will receive.

We place blacklisted mail into quarantine, we do not silently delete any messages.

You can always use whitelisting rules to allow any mail from a blacklisted country to pass without inspection.

For more information on this topic, check our post on country blocking.