Magnifying glass finds email filtering fingerprints

Email Filtering: The Key to Deliverability

Questline sends a lot of email for our energy utility partners. By far, we find Cloudmark responsible for more email filtering and blocking than any other source. But you’ve probably never even heard of Cloudmark. Let’s uncover what this company does and why it’s so different from your average spam filter.

What is Cloudmark?

Cloudmark is one of the largest providers of anti-spam solutions in the world and protects more than 1.6 billion mailboxes. Their technology is used by nearly every major internet service provider in North America, including Comcast, Cox, Earthlink, AT&T, Sprint, Nextel and more. Whether you’re sending to a residential audience, small business owners, or even large business customers under corporate domains, your messages are almost guaranteed to be analyzed by Cloudmark.

How does Cloudmark email filtering work?

Cloudmark offers many software products and services to email providers. You’ll find their filtering technology at multiple levels of an ISP messaging system. But what makes Cloudmark unique is its innovative use of crowd-sourced spam detection that goes far beyond keyword scanning or IP reputation metrics.

Every message that passes through Cloudmark’s system is “fingerprinted” by complex algorithms that analyze the header, body and attachments. Cloudmark then uses its entire global reputation network to identify fingerprint patterns in messages that have hit spam traps or have been marked by your customers as spam. These patterns are used to identify other incoming messages and determine if they are delivered, blocked or sent to the junk folder. And it’s all done in real time. We’ve seen instances where a large marketing campaign was fingerprinted early in the deployment; before the send could complete, Cloudmark was already sending larger percentages of the mail to junk folders.

The most important thing to remember is that if your messages are marked as spam by customers or you’re using poor list hygiene practices, you will experience deliverability issues with almost all of Cloudmark’s 1.6 billion mailboxes. Yikes!

How can I avoid a Cloudmark fingerprint?

Cloudmark technology is intended to support legitimate senders by promoting email best practices, such as:

  • Maintaining consistent branding, sending domains and domains in call-to-action links
  • Using feedback loop data to remove customers who mark messages as spam
  • Employing dedicated IPs and avoiding distributing mail across multiple email providers
  • Suppressing inactive customers to increase engagement and eliminate spam traps
  • Avoiding email appends, list rentals and purchases
  • Following MAAWG Sender Best Communication Practices

Because Cloudmark email filtering is largely tied to customer complaints and spam trap hits, following best practices like these will not only help prevent blocking by Cloudmark, it will also help with other reputation-based and engagement-based spam filtering.

Questline deliverability support

Questline’s Engage platform already takes care of the technical details required to evade Cloudmark fingerprinting. And our Client Success team helps ensure our clients’ mailing practices exhibit the positive behaviors that Cloudmark and ISPs are watching for. But if you’re sending mail with other providers or managing your sends internally, this is an area you’ll want to pay serious attention to.

Learn how Questline’s digital deployment expertise prevents email filtering to get your messages into customer inboxes.