- Overview of DNS Whitelists at spamlinks.net http://www.spamlinks.net/filter-dnsbl-lists.htm#whitelists
- verizon.com (for their customers and ISPs): http://www.verizon.net/whitelist
- aol.com (including other information for postmasters): http://postmaster.aol.com/Postmaster.Whitelist.php
- Whitelist of the Spanish Abuse Forum (Foro ABUSES): http://www.rediris.es/actividades/abuses/
- Marc Perkel from http://www.junkemailfilter.com/ maintains an automated white-/yellow-/blacklisting system. Details at http://wiki.ctyme.com/index.php/Spam_DNS_Lists (the remainder of this wiki is also worth a read).
- Returnpath Certification for Commercial Senders http://www.returnpath.com/solution-content/certification/
- Certified Senders Alliance (paid whitelisting service of the german ECO organisation) https://certified-senders.eu/
- ISIPP (Institute for Spam and Internet Public Policy) http://isipp.com/: Commercial services to help mass-mailers improve delivery rates.
- swisswhitelist.ch is a new service by nextron, a swiss Internet solutions company.
- A blog posting by Stephan Mund with interesting details about inclusion on various commercial whitelists (and dnswl.org).
E-Mail Reputation – Protect against false positives