Email Sender Authentication Checks On the Rise, According To Lyris’ EmailAdvisor Deliverability Study

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Q2 Study Reveals Shifts Among Top 10 U.S. ISPs According to Inbox Delivery, Significant Increase in European ISPs’ Junk/Bulk Rates

PDFs and other files may have been safe a year ago, but today they’ll attract a higher spam score. And next quarter the scoring will change yet again. This is why it’s important to use a deliverability monitoring tool that’s able to test every campaign according to the latest requirements and protocols.

A new email deliverability study signals an increasing reliance on the Sender Policy Framework (SPF) authentication method to determine whether the email is legitimate and should be delivered to the inbox. This means that marketers should make sure their SPF records are up to date, if they want to maintain their inbox delivery rates for their permission-based messages.

That’s a key finding of Lyris’ EmailAdvisor ISP Deliverability Report Card for Q2 2007, a quarterly research study that monitors deliverability rates for permission-based email marketing messages. The study measured the full delivery trajectories of more than 436,000 permission-based email marketing messages using ISP domains in the United States, Canada, Europe and Australia. The complete PDF report is available at

According to the study, permission-based email messages make it to U.S. ISP inboxes roughly 75 percent of the time. led the pack with 97 percent inbox delivery, a full 10 percentage points higher than second place RoadRunner SoCal – both of which didn’t even make the top ten last quarter. Rounding out the top performers – all achieving inbox delivery rates higher than 80 percent – are Verizon, USA, Compuserve, IWon, AOL, Juno, Mac and Netzero.

But for marketers looking for ways to improve inbox deliverability, the most relevant finding from this quarter’s report is the appearance of SPF authentication checks in the list of the top ten content triggers that ISPs check, according to Stefan Pollard, Director of Consulting Services at EmailLabs, which along with J.L. Halsey’s Lyris and Sparklist brands has integrated with the EmailAdvisor deliverability monitoring tool.

“This is the first time we’ve seen SPF checks start to creep into content filter tests, which means that receivers are starting to verify that a sender’s SPF authentication record is accurate,” said Pollard. “This is new. And the good news is that it’s an easy fix for marketers – in fact, it’s completely in the sender’s power to make sure the records are accurate at all times. Don’t assume it’s the responsibility of your system administrator. If you’re responsible for the email program, you need to realize the importance and test it yourself.”

Sender Credibility is at Stake

Failing an SPF check carries a heavy penalty – 2.6 points from the current Spamassassin test, on a Bayesian scale that identifies a message as spam when it reaches 3.0 points or higher. That’s more than double the penalty for any of the other top ten spam triggers identified.

SPF checks compare the sender’s return path domain and the IP address to a list of approved IPs the sender includes in their DNS zone. The company in charge of a domain (for example, must keep the list of approved IPs up to date. A common – but easily rectified – reason for failing an SPF check is when a company changes IP addresses or email service providers, but doesn’t update its SPF records.    

To find out if they would pass or fail an authentication check, marketers can simply look at their message headers in the major Web-based email platforms (Hotmail, Gmail, Yahoo, etc.). The header should read “SPF PASS” or for domain keys either display a trust icon or the key check results. To learn more about authentication, read the Direct Marketing Association’s primer at

Spammers’ Methods Continue to Evolve

According to Dave Dabbah, Vice President of Marketing for Lyris, between the Q1 and Q2 surveys, there’s been a decrease in image spam and an increase in spam that uses PDF, PowerPoint and Excel files.

“It’s important for email marketers to keep track of spam trends, because as spammers change the way they attack, the ISPs change the way they monitor and filter individual messages,” said Dabbah. “PDFs and other files may have been safe a year ago, but today they’ll attract a higher spam score. And next quarter the scoring will change yet again. This is why it’s important to use a deliverability monitoring tool that’s able to test every campaign according to the latest requirements and protocols.”

‘Junking’ Legitimate Messages Still a Problem

Marketers sending permission-based emails to U.S.-based ISPs still land in the junk/bulk folder almost 16 percent of the time. XO Concentric far exceeds any other ISP – banishing 56 percent of invited email to the junk/bulk folder. Next in line are SBC Global and Bell South, both junking 30 percent of permission-based email, and Yahoo at 26 percent. MSN Network, GMail and Hotmail all come in at 18 percent. Rounding out the top ten are PeoplePC, USA and Earthlink. At the other end of the spectrum – AOL only delivered 1.94 percent to the junk/bulk folder.    

Marketers sending to European ISPs face even more trouble. More than 20 percent of permission-based emails were sent to the junk/bulk folder – that’s almost three times more than last quarter.

About the Study

From a period beginning April 1, 2007 and ending June 30, 2007, the Lyris EmailAdvisor service monitored the full delivery trajectories of 436,558 production level, permission-based email marketing messages sent from 69 different businesses and non-profit organizations to multiple accounts at 58 ISP domains in the United States, Canada, Europe, and Australia.

Messages were chosen to represent a cross-section of legitimate publishing activities. Examples of email publications monitored by the study include publishing, B-to-B marketers, retail, travel and finance, among others. In all cases, the recipients to whom the emails were sent had made an explicit "opt-in" request to receive the messages at the specified email addresses.

*Additionally, 1705 unique emails from the same set above were run through a content score application using the Spam Assassin rule set (a Bayesian filter that applies point values to multiple possible spam related signatures and sums to an aggregated point total for decision-making purposes) to determine the overall suspected content score that would determine the likelihood an email is determined to be considered "spam."

About Lyris Technologies

Founded in 1994, Lyris Technologies provides leading-edge email marketing software solutions to more than 5,000 customers worldwide. Our suite of products, led by our flagship product ListManager, offers powerful tools for opt-in email marketing, list management, database segmentation, and deliverability assurance. Lyris offers both hosted and software versions for publishing email campaigns, newsletters, and discussion groups. Our commitment to permission-based marketing, outstanding deliverability rates, and our extremely positive ISP relations make Lyris' solutions among the best-selling email marketing applications on the market today. Based in Emeryville, California, Lyris — along with Email Advisor, ClickTracks, EmailLabs, Hot Banana, and Sparklist — are brands of the J.L. Halsey Corporation (OTCBB:JLHY), a leading provider of technology solutions to marketers at mid-size businesses.

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Ken Greenberg
Edge Communications, Inc.
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