How to check your domain reputation

While IP reputation is still important, most people are sending mail over an IP shared with other senders. That has always watered down the IP’s relevance to an individual sender — but with the prevalence and disposability of IPv6, we’re seeing an even greater shift in how email reputation is calculated.

Now more than ever, domain reputation is a significant factor in deliverability. It’s considered everywhere your domain is used including your message’s content, your brand assets, and of course email authentication.

How is Domain Reputation calculated?

To determine domain reputation, receivers keep track of every way your domain is used in a message and how that message ends up performing in the inbox. Based on this data, major ISPs use complex algorithms to ultimately “score” your domain, checking that score when scanning future messages to establish a level a trust. The better your domain reputation check at a particular receiver, the less likely your future messages will end up rejected or in a spam folder.

So that means you don’t have just one big domain reputation floating out there in cyberspace. Instead a domain has countless reputations unique to the proprietary scoring processes a specific receiver employs. Plus you’re probably not sending the exact content and volume of messages to every single receiver, so as an example, it’s expected that Gmail’s seen at least slightly different engagement from their users than Yahoo.

Domain Reputation lookup tools

It’d be great to know exactly what everyone thinks of your domain, but the more a receiver shares about how they determine who’s good, the more spammers and other nefarious senders will take advantage of that data to beat the system. As a result, most receivers keep their judgements about reputation private. There are, however, a few free services that can aggregate multiple receivers’ data to give you some general insight into your domain’s health overall.

First check out Talos Intelligence provided by Cisco that associates your “web reputation” with messages sent over various IPs. If there are significant problems that pose a deliverability risk, you’ll likely spot them here. A “neutral” reputation there, however, typically means there’s little data available for your domain (low volume).

There’s also third-party filtering software some use in their corporate or university mail servers. You can run a quick search in these public databases to determine if your domain is blacklisted or considered “risky”. Two of the most popular are Barracuda and McAfee. Beyond that, tools using open source SpamAssassin filtering can help identify any domains in your content and email headers that could hinder delivery.

If there’s been some risky behavior on behalf of your domain, that could sometimes cause it to appear on a public block list. You can check your domain against many popular block lists at once using MXToolBox or They’ll include links to get more information about any listing, which usually includes options to resolve it to minimize any impact on your deliverability.

Finally, there are certain receivers who directly share their internal reputation score for your domain. You can check domain reputation there for free as long as you have high enough volume to anonymize the data. The most notable is Google Postmaster Tools, a top receiver for many senders. You’ll get an exact reputation grade from Google that directly affects deliverability to Gmail recipients. Shifts in your GPT domain reputation can be traced to shifts in deliverability to recipients directly.

Even if Gmail isn’t your biggest receiver, data on how one entity views your domain is excellent insight into how other receivers might determine your reputation. And there’s some good news for Eastern European brands — Yandex and developed their own postmaster tools you can use for free.

If you’re not seeing very much data about your domain, don’t sweat it! It likely just means your volume isn’t large or consistent enough yet. Just make sure you’re working with highly reputable ESPs to optimize deliverability. In the meantime, set up custom DKIM and Return-Path domains so that as your email volume grows, you’ll be able to build a standalone domain reputation based on your own good sending practices.


[Originally posted here.]