Set up DMARC and see who's sending email using your brand's domain.

The importance of domain reputation

This week I spent some time working with a customer whose emails were continually going to Spam in Gmail. When this happens, we don't take it lightly. Any email going to spam, especially transactional, is a Red Flag in support for us.

Learn more about transactional email best practices.

Dana asked me to take a deeper look at the case and see if I could figure out the cause. Gmail is nice enough to give some hints at why a message ended up in spam. In this case, it displayed the following:

Why is this message in Spam?

I spent some time looking at several of the usual suspects:

  1. Are they using DKIM, SPF, and DMARC?
  2. Is a domain in their links on a blacklist (used mxtoolbox)
  3. Can we test different content scenarios?
  4. What if we try a different Return-Path domain other than Postmark's?
  5. What if we try a different email server?

After all of these attempts, the messages still went to spam. The most surprising one that raised an eyebrow was the fifth point. Even though we used another email server (their own server) the message went to spam. This meant one of two things: It's either content related or domain related. 

Since we already tested content, I focused strictly on domain reputation. The best way to troubleshoot domain reputation is with Gmail's Postmaster Tools. I asked the customer to set up the domain and send back some of the reports. That's were we found it.

Gmail Domain Reputation
The data from Gmail's Postmaster tools showed that the only High reputation emails were coming from Postmark. Their other emails were holding them back.

The useful tool in this case was Domain IP reputation. This tool will show the reputation for your domain across the IPs that are sending email for your domain. In the chart above, most email traffic for this domain is Low or Bad, a place I hope no one ever gets to in Gmail. If you click on each area, it will display the IP addresses that sent traffic.

What we noticed was the green, or High reputation, was from Postmark's IPs. It was their high engagement transactional email. The red, yellow, and blue were IPs used for marketing message from another system or service. We are still trying to track down the sources more to figure it out. 

Domain reputation matters, and it's portable! #

The key lesson to take away here is that even though the customer was sending through Postmark, their sending practices from another source affected their delivery. The spam decision was based on domain reputation, something that is entirely out of our control as an ESP. The best we can do is help the customer troubleshoot and identify the problem.

The second lesson is that this is real proof around the difference between bulk/marketing email and transactional email. The only green lines in that chart were for transactional, which have higher engagement and therefore higher reputation. This is why we focus solely on transactional email to ensure we have the best reputation in the industry. It's not fluff, it's real and it has an impact.

Domain reputation is the future #

I suggested the importance of domain reputation almost five years ago in my post about why Dedicated IPs offer false promises. We've come a long way and it is now a reality. This shift is extremely important because it places responsibility not only on the ESPs, but on the domain owners to maintain a great reputation and to abide by the best sending practices, such as TLS, DKIM, SPF, and DMARC.

I strongly encourage anyone reading this to enable your domain on Gmail's Postmaster Tools. You might find something surprising.

Chris Nagele

Chris Nagele

Love to travel with the wife and kids. Wannabe race car driver. Not so healthy obsession with Building Science.