Seventeen percent of permission-based e-mail was incorrectly blocked or filtered by the top 12 Internet service providers in the first and second quarters of 2003, according to a study by Return Path Inc., an e-mail change-of-address, list hygiene and consulting firm.
This represents a 2 percent drop in delivery rates from fourth-quarter 2002, according to a statement the Superior, CO-based company published yesterday.
In Internet service providers' ongoing battle to prevent spam from crushing their systems, they use filters to weed out as much unsolicited e-mail as they can while still delivering e-mail their subscribers want. For example, they block e-mails with certain words in their subject lines, such as “free,” it is reported.
However, the stricter the filtering, the likelier it is that permission-based e-mail will get blocked as well. As a result, incidents of incorrectly blocked permission-based e-mail, or so-called false positives, are reportedly on the rise.
Mail.com and NetZero had the highest percentage of false positives, at 38 percent and 34 percent respectively, Return Path said. CompuServe and AOL incorrectly blocked 31 percent and 25 percent of permission-based e-mail, respectively.
BellSouth and EarthLink incorrectly blocked 7 percent of permission-based e-mail, Return Path said, and Yahoo had the lowest false-positive rate at 4 percent.
Return Path defined permission-based e-mail as e-mail sent to addresses of people who opted to receive the messages, and that contained clear notice that the communication was permission-based as well as a choice to opt out, spokeswoman Jennifer Wilson said.
The study, by Return Path's recently acquired e-mail deliverability division Assurance Systems, tracked the delivery, blocking and filtering rates of 9,956 e-mail campaigns sent by clients, the company claims.
Return Path acquired Assurance Systems in June. Assurance debuted in October offering three services:
· Message Checker automatically identifies the elements of e-mail marketing campaigns that are most likely to trigger spam filters, letting marketers make their messages look less “spammy” before sending a campaign, the company said.
· Mailbox Monitor lets companies monitor when their messages are not getting through various ISPs.
· Blacklist Alert tells companies when their services have been put on any of more than 300 blacklists, or “blocklists” as anti-spammers and e-mail administrators call them. Blocklists, such as Spam Prevention Early Warning System and Spamhaus.org, maintain lists of Internet protocol, or IP, addresses suspected of being sources of spam. Many ISPs and mail administrators use these lists to block incoming e-mail from IP addresses listed.