DNS Whitelist

Avoid wrongly sending good emails to the spam folder

Monitor and manage the reputation of your mailservers

Dnswl.org is the leading email whitelist, also called DNS whitelist (DNSWL). It reduces the risk of false positives by publishing the outgoing IP addresses of  mailservers in different trust levels.

Dnswl.org provides reputation information about email senders. The list is used by over 100’000 companies and organisations with tens of thousands of requests per day. The list contains over 600’000 entries of “good mailservers”, including a growing amount of IPv6 entries.

Beyond the 100’000 large users, dnswl.org data is used by more than 5 million low-volume users on a daily basis.

Close to 20% of the 600’000 entries are managed by the owners themselves, with over 10’000 accounts on our self service pages.

Your email filter should try to avoid tagging messages as spam if they come from one of the good mailservers we list, which are assigned into one of four trust levels:

Trust Level Description
High Highly unlikely to send spam, and expected to be very fast in remediating issues.
Medium Rare spam occurrences, corrected promptly.
Low Occasional spam occurrences, actively corrected but less promptly. This is the default for most categories.
None These are legitimate mail servers, but they may also emit spam or have other issues from time to time.
This is the default for some categories (eg Email Marketing Provider), and also includes some large email service providers.

What does it cost?

Access for non-commercial users doing fewer than 100’000 queries per day is free. See the subscribers page for details.