Anti-spam researchers at the Spamhaus Project have introduced a whitelist of known benign internet mail servers.
The approach sits alongside Spamhaus' well-established blacklist of bad mail servers to make it easier for mail server operators to filter junk from incoming email traffic. Qualified corporations such as banks, law firms, airlines, medical centers and government agencies, and transactional email from automated billing systems, ecommerce servers, online banking and booking systems are all candidates for the whitelist.
Using a whitelist in addition to filtering email traffic by content places a lower performance overhead on spam filters. It also makes it less likely legitimate transaction-related emails or the like will be marked as spam by scoring systems, content filters, local "blacklists" or poor filtering choices. For email senders, the technology makes it far less likely that important emails will either be delayed or classified as junk.
The Spamhaus Whitelist was launched as a beta with inclusion on the list being invitation only, from someone who already has a whitelist account. Whitelist account holders "are chosen by others who trust them; you cannot simply apply," according to Spamhaus.
Spamhaus is reserving the right to revoke whitelist status for any email etiquette transgressions, such as the distribution of bulk mail of any type. The whitelist will be maintained in both IP addresses and domain name forms as two separate, but matched, lists. Controls mean no domain or IP address that is on the Spamhaus Project blocklist can ever be whitelisted.
More information on the whitelist can be found from Spamhaus here. ®