Answer: Marketers are justifiably concerned that they might unwittingly end up on an e-mail block list—a list of e-mail server IP addresses of known spammers. Block lists are used by ISPs to determine whether an e-mail should be blocked. Marketers that wish to take a proactive approach to getting their legitimate e-mail delivered need to understand safe lists (a.k.a. white lists). Safe lists are basically lists of known "good citizen" senders of commercial e-mail.
Safe lists can be one of three kinds:
- Recipient-maintained lists of known senders;
- ISP-specific lists of senders who have applied for and met an ISP’s specific criteria for inclusion;
- Third-party lists of certified (sometimes called accredited) senders that respect e-mail-sending best practices.
A third-party list represents the most effective of the three, since it is referred to by all the major ISPs and the market-leading spam filters.
Becoming a certified sender of "legitimate" e-mail is not difficult. A reputable accreditation agency can tell a marketer whether it’s on a block list and if so, why. More important, the marketer can learn how to improve its sending practices to avoid being block-listed. Some go even further, providing an accredited sender with a "seal of approval" that is recognized by ISPs and ensures its e-mails are safely delivered.
Des Cahill is CEO of Habeas Inc., a California-based company that defeats spam by enabling trust in legitimate email. He can be reached at firstname.lastname@example.org.