Because Spamhaus can't continue forever funded with the personal resources of its team, or rely indefinitely on donated servers and network resources, a new funding model was adopted in 2004. The new model permits Spamhaus to continue to offer services free of charge to individuals and small businesses, while enlisting the help of MXTools to manage subscriptions from large commercial/corporate networks to the Spamhaus ‘Data Feed’ data synchronization service. Data Feed is a resource-intensive service which Spamhaus currently supplies exclusively to large ISPs and corporations with heavy email traffic.
Spamhaus has devised a pricing structure designed to be acceptable to Data Feed users (the few thousand corporations taking twice-hourly Spamhaus DNSBL transfers) and which takes into account the large amount of universities and non-profits, and which caps the subscription fee with an "unlimited users" rate - so current giant Free Mail providers with millions of users each needn't worry, in fact they should find it very affordable.
With this model, the prime objective of keeping Spamhaus available and reliable to the millions of users who rely on our anti-spam systems can be assured Spamhaus will be here for as long as spammers plague the internet.
Free Use
Spamhaus serves billions of DNSBL queries to the world every day, from its over 45 public DNSBL servers spread across 18 countries. This free public DNSBL service is sustained thanks to donations of equipment and bandwidth by some of the internet's best organizations and networks and is backed financially by an autonomous commercial service that delivers Spamhaus data to ISPs, commercial networks and spam filter services. To qualify for free Spamhaus DNSBL query service, mail server operators need to ensure they meet the criteria for free use.
Use of the Spamhaus DNSBLs via DNS queries to the Spamhaus public DNSBL servers is free of charge if you meet all three of the following criteria:
- Your use of the Spamhaus DNSBLs is non-commercial*;
- Your email traffic is less than 100,000 SMTP connections per day;
- Your DNSBL query volume is less than 300,000 queries per day.
If you do not fit all three of these criteria then please do not use the Spamhaus public DNSBL servers, instead see 'Professional Use' (below) which delivers our DNSBL data to your servers. If you are in any doubt as to whether you fit within our free use criteria, or think you may be likely to soon exceed our free use criteria, please switch to 'Professional Use'.
Spamhaus monitors use of its public DNSBL servers to identify installations exceeding the free use criteria in order to prevent a minority of heavy users from degrading the quality of the service to all other users of the free public DNSBL servers.
Caution: If your usage should exceed the free use criteria your access to Spamhaus's public DNSBL servers is very likely to be cut off without warning.
Professional Use
Use of the Spamhaus DNSBLs by ISPs, organizations and networks with email traffic higher than 100,000 SMTP connections per day or making over 300,000 DNSBL queries per day, or by commercial spam filter services, requires a subscription to the Spamhaus DNSBL Data Feed Service, a service designed for users with professional DNSBL query requirements.
Data Feed provides data synchronizations of the Spamhaus DNSBLs (SBL, XBL, PBL and also the DROP list) to a local DNS server on your network. Your mail servers therefore query a local DNS server on your network instead of going out to our public servers all over the world. This means DNSBL queries are super-fast, entirely under your control, and the service comes with a Service Agreement and Technical Support.