DNSBL-blacklist — lists of hosts that are stored using the DNS architecture. Commonly used to combat spam. Mail server contacts the DNSBL, and checks the availability of the IP address of the client from which it receives a message. If the answer is that it attempts to receive spam messages. The sending server reported error 5xx (fatal error) and the message will not be accepted. The sender's mail server creates new "renounced the receipt (NDR) to the sender of mail".

Our service will help you determine whether your IP address within the most active SPAM databases. If your IP will be present at one of the bases, you will receive a dedicated red notice in front of the base. Clicking on the address database you will be able to apply for the removal of your IP address from the SPAM database.