Google postmaster tools for anyone unfamiliar with it is a system setup by Google where you as a domain owner can put in your domain and get various metrics about your domain and how it is perceived as an email sender. I discovered this tool 10 years ago when talking to my customer service rep for the current email service provider that I was dealing with for sending our newsletters at my company. She had told me that this is one of the better ways to track domain reputation. If your domain reputation is too low Google and other email service providers will either place newsletter emails in the spam box… Or worse will not deliver them at all.
Along with domain reputation you’re able to see spam rate which gives you the number of spam or volume of users that are reported your emails as spam, this hopefully is always under 1%. There is also IP reputation which is the sender’s IP. So while it might not be the domain of your website if your ESP for newsletters has you want to shared IP address there could be a bad neighbor bringing you down.
There’s also a metric for delivery errors. This basically tells you the total number of rejected or temp failed newsletters. This is usually in a percentage as well and should again always be close to zero.
Anyhow as of October 31st 2025 Google has updated postmaster tools. The latest postmaster tools has everything from the original postmaster tools with the exception of domain reputation and IP reputation. Google remove these two stats because they viewed it as being too confusing for the users. However they are continuing to use it internally. Putting on my tin foil hat here I believe that it was Google removing it because spammers were figuring out how to game the system and looking at that they could easily say whoop our domain has crossed over into mediums probably going to hit low soon so let’s get a new domain and start sending from. It’s a valid point but for people who were using it legitimately anytime that I saw something go into medium I needed to do an investigation. Now I don’t have that tool to tell me to start or stop.
I’m going to file this under email and and Enshittification
