The reading level for this article is Novice

The rules have changed regarding actually getting your email marketing messages into the recipient’s inbox. Given the unfortunate explosion of abusive email marketing practices, most of the major email providers either have implemented or are about to implement new techniques to protect their subscribers from unwanted emails. This article focuses on the increasing use of blacklists and whitelists to filter incoming messages, and what legitimate email marketing professionals need to be doing now to protect their subscriber lists.

Avoiding The Dreaded Blacklist
A blacklist is list of senders whose email is blocked from getting thru to recipients. For various reasons, which depend entirely on the policies of each individual blacklist, the maintainer of the list has indicated that the sender should not be allowed through to recipients. Email recipients who subscribe to the blacklist check all email that they receive against the list. If a sender’s email server is on the list, instead of being delivered the message will be deleted, blocked, or filed into a special folder for what is presumably unwanted email.

The main reason servers are blacklisted is from sending large numbers of unwanted emails. Assuming that a sender has policies and procedures in place to avoid this, there are several other reasons why an email server may still end up blacklisted. One frequent reason for blacklisting is problems with the sender’s email server settings that allow for unauthorized email to be sent by individuals other than the server’s owner, known as an "open relay". Any competent systems engineer can easily fix this common problem. Another reason a sender’s email server may be blacklisted, is that the IP address of the server may be within a range of IP addresses that the blacklist maintainer considers to be a source of unwanted email, such as an ISP that has hosted questionable senders before. A third reason may be that an IP address newly being used by a legitimate sender may have been recycled from one used previously by a questionable sender.

Some blacklists appear somewhat arbitrary, and others have policies that are largely perceived as fair. Some have specific rules they follow; others act on the whims of their list administrators. Some allow for resolving disputes, others have the final word and that’s that. Although the first blacklist users have shared the same lists across large numbers of different email servers and different organizations, the widely ranging opinions on what constitutes "unwanted" have made such generic solutions unwieldy and impractical for business users. Newer, more advanced blacklists are now created and shared within single organizations, or even based on individual user preferences.

Getting On The Whitelist
Whitelists are the exact opposite of blacklists. Where a blacklist specifies who is to be kept out, while allowing all others to pass, a whitelist only allows those who are already on it to get thru, like a guest list at a nightclub. Any email that is not on the whitelist is filtered to a "junk mail" or "unknown senders" folder. An extension to the whitelist concept is a "challenge-response" system, as more fully described in the article, "Bounced, Blocked, or Bad?" ( A challenge response system is just a fancy way of getting unknown senders added to a recipient’s address book, by having to verify their identity (or at least their email address) before email will be delivered.

Regardless of what form of whitelist the recipient’s email server uses, due to their recent increased popularity, senders of email marketing need to get added to recipients’ address books as soon as possible in order to keep response rates up. Finally, to get messages passed thru whitelists, it is very important that senders are consistent and use the same return email address for all email marketing communication. Otherwise, there is no point in asking recipients to add you to their address books.

Big Changes At The Major Providers

  • America Online 9.0
    Although a limited form of whitelist has been in AOL software for some time, the latest version of AOL has some new behaviors that directly impact email marketing. The most important of these is that images in emails are now blocked (in other word, not displayed) unless the sender’s from email address is already in the recipient’s address book. Also, a different icon is used in the list of new messages for senders who are in the address book.

  • Hotmail
    Hotmail is just about to release an upgraded version of their service that will include whitelist functionality. The main page that Hotmail users will see will be called the "Today" page. This page will display only email message that are on the recipient’s contacts and safe list. All other messages will only display on a separate page for unknown senders.

  • Yahoo
    Yahoo is releasing a version of their service that includes a new feature called "message views". This feature ensures delivery to the main inbox for any sender already in the recipient’s address book. All other email ends up in an unknown senders folder.

  • United Online (Netzero + Juno)
    Netzero’s and Juno’s Platinum service have both individual blacklist and whitelist features. The whitelist requires that senders be added to the Contacts in the recipient’s Address Book, or else have messages placed in the Junk Mail folder.

  • EarthLink
    EarthLink was the first of the major email providers to adopt a whitelist system, a move that is rapidly being mimicked by the other major providers. Their offering is a challenge-response system they call spamBlocker, which requires that senders be added to the recipient’s address book in order to ovoid their messages going into the "Suspect Email" folder.

Being on a blacklist does not automatically mean the sender is not legitimate, and not being on any does not grant legitimacy, since true spammers move around as well as hide their identities. This is why whitelist based solutions appear to be gaining in popularity over blacklists. The problem for email marketing is that whitelist based "solutions" may result in your messages getting tossed instead of read. There is a bit of work involved getting your "from address" added into recipients’ address books, but it is an investment you need to make. The bottom line is that you need to get recipients to add you to their address books, and you need to do it as soon as possible.

Getting your email marketing message across requires that the email actually be delivered, so you simply cannot run afoul of the major email service providers. If you follow legitimate policies, entirely avoid questionable email lists, and respect the service providers whose bandwidth you consume, you will be able to use email marketing to enhance your business.

This Web Marketing article was written by Ron Evans on 3/21/2005