The Polish RBL server is an online service focused on helping email administrators combat spam and poor netiquette. It publishes blacklists of spam-related domains and IP addresses, alongside black and white lists, for use in filtering email. The service works like other real-time blocklist (RBL) systems, allowing mail servers and spam filters to check whether a domain or address appears on a list.

The site recommends starting with the RBL through SpamAssassin, using a low score to observe which domains and IP addresses are listed before making broader changes. It cautions that lists marked with “h” may be highly restrictive and advises using them with spam filters rather than rejecting mail directly, since this can produce unwanted results. After reviewing list entries, administrators can choose whether to connect selected lists to their mail transfer agent.

The website also provides technical guidance for Exim, Postfix, SpamAssassin, DKIM, DMARC, and SPF, as well as regulations and instructions for requesting delisting, including guidance for hosting providers.