• Best Practices

Google Postmaster Tools: Understanding Sender Reputation

Cameron Henry
5 min read

Tracking your sender reputation can feel a lot like tracking bigfoot. You do your best to key into the clues left out in front of you by the mysterious inbox service providers (ISPs) about your track record, but their true opinions on your sender reputation remain elusive.Unlike cryptids, which aren’t real (we think), ISPs are very real —  and not many of them offer the transparency needed in order to adapt your sending practices to avoid spam filters. Thankfully, Google Postmaster Tools is just that: a tool that gives you direct insight into your domain reputation, IP reputation, and more.

According to several online statistics, Gmail had around 1.5 billion active users as of October 2018, and the Gmail recipients can make up sometimes as high as 60% of a company’s list.

Generally speaking, if you are a high volume sender and send a large portion of your email to Gmail recipients, Google Postmaster Tools can help you monitor your performance and get ahead of deliverability issues before they happen. Even if Gmail is not your primary focus, understanding how your mail is perceived by Gmail can give you a better understanding of how you are perceived elsewhere.

Where do I start?

Getting started with Google Postmaster Tools is straight forward. First, add your authenticated sending domain; This can either be your root domain or subdomains depending on how you want your information presented. If you choose to add your root domain, data will be aggregated across any related subdomains and IPs. Should you segment your traffic into multiple subdomains, it’s a good idea to add each one to Postmaster Tools separately to keep your data points focused.

Once you get set up and running, Google will give insight into several data points organized into different postmaster tools dashboards. These data points include a couple of metrics you might be familiar with and a few that speak more to your sending habits or processes, such as:

Spam Rate

The spam rate dashboard tracks how many users are reporting your messages as spam. Tracking spam complaint rates is a serious business, and ensuring you are taking action on those complaints is even more important. By gaining insight into the volume of these complaints and using it as a data point to compare against your domain or IP reputation can give senders like you a possible cause to reputation dips.

Domain Reputation

As I mentioned earlier, in order to track your domain reputation you can either add a root domain which will show the statistics for that domain and any subdomains, or you can add individual subdomains and track reputation individually. If you are using subdomains at all, it is a good idea to add them individually to keep an eye on the macro level reputation and get an idea if that content is hitting an inbox or getting sent straight to spam. Reputation for both domains and IPs is tracked with simple color coding, ranging from a deep red to green representing bad, low, medium, and high. The nicer the color, the more likely your messages are going to that sweet sweet inbox and not taking the sad train into the spam folder.

Don’t be that guy.

IP Reputation

Similar to domain reputation, your IP reputation plays a role in deliverability as well. Again, this reputation is color-coded the same way the domain reputation is coded and represents the likelihood that messages will be delivered to the inbox— except for your sending IP addresses. It is important to note that dedicated IPs will give you a much better measure of control over these statistics, whereas shared IPs will fluctuate often regardless of your actions. 

Feedback Loop

For email senders that have signed up with Google’s Feedback Loop (FBL) to track campaign specific complaint rates, you may have access to the Feedback Loop Dashboard. The dashboard will provide two graphs to track the Average Feedback Loop Spam rate across any identifiers (specific campaigns, customers, or “other”) flagged by the FBL, as well as an Identifier Volume Graph showing the number of unique identifiers broken down daily.


This handy dashboard tracks your messages that have passed DMARC, SPF, or DKIM authentication. Here you will find a simple graph that displays the percentage of messages that have passed authentication. If you do have any authentication related issues, such as no published DMARC, you may see that percentage dip or sit at 0%.


The Encryption dashboard will break down the percentage of inbound or outbound mail that has passed TLS compared to all mail coming from or being sent to your domain. Essentially, it gives you a better idea of what your email volume overall looks like. It’s a simple, but important dashboard to know. 

Delivery Errors

To get an idea on your delivery rate, I suggest looking at your Delivery Errors dashboard. Here you can see the volume of messages that were either rejected or temporarily failed — including a reason why the failure occurred. So if your messages were rejected due to a misconfigured DMARC policy, that information will be available on that dashboard.

Share with your team

When it comes to email insights — sharing is definitely caring. Should you need to provide share access your team members (or your Technical Account Manager if you are on Mailgun’s Managed Deliverability Services) to these dashboards, all they need to have is a valid Google account. This share feature is similar to other Google apps, but should you run into any problems you can ask for help through their platform – https://postmaster.google.com

Context clues

I cannot stress enough how essential Postmaster Tools is for troubleshooting one’s sender reputation. Sure, it doesn’t speak to every ISP’s perception of your sender reputation, but given that Gmail is one of the larger ISPs, we’re confident that problems seen with Gmail are likely happening with others. Address the issues you see in Postmaster Tools, and your email deliverability (and your TAM) will thank you.

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Last updated on August 28, 2020

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