SPF checks are a growing part of deliverability authentication

A study released today revealed that marketers should begin attending to Sender Policy Framework (SPF) authentication to improve e-mail deliverability.

For the first time, according to a statement from Stefan Pollard, director of consulting services at EmailLabs, SPF checks are becoming part of content filter tests done by Internet service providers. These checks, which compare the sender's return path domain and the IP address to a list of approved IPs the sender includes in their DNS zone, are often failed because a company changes IP addresses or e-mail service providers, and doesn't update its SPF records.

The Lyris' EmailAdvisor ISP Deliverability Report Card for Q2 2007 measured the delivery path of more than 436,000 permission-based e-mail marketing messages using ISP domains in the United States, Canada, Europe and Australia.

Increased attention to SPF ratings requires marketers to ensure that their SPF records are current in order to maintain delivery rates for permission-based messages. SPF record maintenance is not something done automatically by ISPs. But failing an SPF check can carry double the spam-rating penalty compared to the other Top 10 spam triggers identified in the study.

According to the study, permission-based e-mail is delivered 75 percent of the time to US ISPs. AIM.com ranked at 97 percent inbox delivery. Other top performers, all of which had delivery rates of more than 80 percent, were Road Runner SoCal, Verizon, USA, Compuserve, IWon, AOL, Juno, Mac and Netzero.

Conversely, XO Concentric was found to send 56 percent of permission-based e-mail from marketers to the junk or bulk folder. SBC Global and Bell South both place 30 percent of permission-based e-mail in junk folders.