When you receive an email from another email address, Dot Easy Australia email servers run a RBL checker on the receiving email against any known DNS Blacklisting companies. The RBL checker is different than Spam Assassin or Box Trapper which is only for filtering and removing emails that go through to your server.
What is an RBL?
An RBL is an Real-Time Black List or also called, a DNS-based Blackhole List (DNSBL), or Blacklist. Companies like Spamcop maintain a database of IP addresses that are reported by consumers as being spam originators. When the server scans an email and finds the sender to be on a blacklist the email bounces to the sender.
Why does Dot Easy Australia use an RBL checker?
Using DNS Blacklisting companies is an industry standard. Not only does Dot Easy Australia uses DNS Blacklists; but, most email servers in the World use them. The DNS Blacklist company will keep a list of known IP addresses that have been reported and verified and sending spam from the server. This forces companies to regulate their servers to prevent hacks and malicious activity from happening on their server.
Can the RBL checker check be disabled?
We will not disable the DNS Blacklist checking on our Shared servers. The DNS Blacklist is the most effective way to keep our shared server customers from receiving unwanted spam from unknown senders.
VPS and Dedicated servers on the other hand can have the DNS Blacklist check disabled in their EXIM software. This will require root access to change and knowledge of the ssh command line. Our Support can disable the RBL checker for you if you cannot.
IMPORTANT! We do not recommend disabling DNS Blacklist checking on any server as this will allow any email IP of known spammers to email your server.
Can Domain or IP addresses be Whitelisted?
We will not whitelist any domain or IP address that is on a known blacklist on our shared servers. Unfortunately, if a sender is on any known DNS Blacklist, they will need to contact their email service provider to have the IP delisted or contact the DNS Blacklisting company them self to have the IP delisted.
On VPS and Dedicated server, you can whitelist IP's and domains for your EXIM to allow particular IP's through to your server. This is a root access change and would need ssh command line experience. You may want to contact support to have the domain or IP whitelisted.