Guides

How to check your domain reputation, receiver by receiver

Last updated 2026-09-09

Your domain doesn't have a reputation. It has several, one per receiver, and they don't talk to each other. Gmail keeps one. Microsoft keeps one, mostly per IP. Each blocklist keeps a yes or no. The tools that print a single score for your domain are scoring you against a model of their own, and no mail server consults it.

So you check with each receiver separately. Start with the one that decides the most of your mail.

Which one should I check first? Google Postmaster Tools. It's the only view that decides delivery at Gmail, and most domains have never set it up.

Google Postmaster Tools is the view that counts at Gmail

Gmail's opinion of your domain is in Postmaster Tools, free, from Google, and reporting on the actual traffic between your domain and Gmail users. If you send any volume to Gmail, this is the page that explains it.

1. Sign in with any Google account and add a domain. Google's instruction is to enter the domain you use to authenticate outgoing email with SPF or DKIM, or both. That's the domain in your DKIM d= tag or your return path, which may be a subdomain.
2. Verify it. Google gives you a TXT or CNAME record to add at your DNS host. Verification is usually immediate and can take up to ten minutes.
3. Open the Domain reputation dashboard.

Google rates a domain at one of four levels. In its own words:

• High: a history of very low spam rates, complying with Gmail's sender guidelines. Mail is rarely marked as spam.
• Medium: a history of legitimate email, but occasionally sends spam. Most mail has a fair deliverability rate.
• Low: a history of sending a significant volume of spam regularly. Mail is likely to be marked as spam.
• Bad: a history of sending a high volume of spam regularly. Mail is almost always marked as spam or rejected.

Two other dashboards matter. Spam rate is the share of your delivered mail that Gmail users reported. Google's requirement, when I last checked, is to stay under 0.10% and never reach 0.30%. The sender guidelines carry the current numbers. Authentication shows what share of your traffic passed SPF, DKIM and DMARC, which is the first thing to fix when reputation is low.

One limit. Google withholds data on days when your volume to Gmail is low, to protect its users. A domain sending a few hundred messages a day to Gmail may see nothing for weeks. Google hasn't rated the domain at all, which is the normal state of a small sender.

Microsoft keeps its opinion per IP

Microsoft's equivalent is Smart Network Data Services, SNDS. It reports per IP address rather than per domain, so you have to own the IP. Sign in with a Microsoft account, request access to the IPs you're responsible for, and confirm through the address Microsoft mails at the network's abuse or postmaster contact.

Once in, SNDS shows each IP's filter result for the day, green, yellow or red, and its complaint rate from Outlook.com users. Microsoft has said trap-hit counts leave the data report from July 2026, so don't plan around that column.

If you send through Google Workspace, Microsoft 365 or any shared sending service, you don't own the IP and can't register it. Your provider does. For a domain-level problem at Microsoft, the route is the sender support form, which is the same page you use to ask for an IP to be unblocked.

Blocklists answer yes or no

A blocklist has no scale. Your IP or domain is on it or it isn't, and a receiver that consults it refuses your mail or doesn't. Two of them are worth checking directly, because large receivers and most mail filters actually use them.

Spamhaus keeps IP lists, queried as one zone called ZEN, and a domain list, the DBL. Look yourself up at check.spamhaus.org, or from a shell. The IP goes in reversed:

No answer means not listed. An answer starting 127.0.0. or 127.0.1. means listed, and the last number says on which list. Run this from your own resolver, or the query is refused. Spamhaus answers public resolvers like 8.8.8.8 with an error code instead of a verdict. Spamhaus delisting reads the codes and covers getting off each list.

Barracuda keeps an IP list used by every Barracuda spam appliance and by anyone else who points at it:

127.0.0.2 means listed. Barracuda delisting covers the removal form.

The multi-list checkers, MXToolbox and the like, query dozens of lists at once. Most of those lists aren't used by anyone who matters, and a listing on one of them changes nothing about your delivery. Read the result for Spamhaus and Barracuda and ignore the rest unless a bounce names one.

Talos is Cisco's opinion

Talos Intelligence is the reputation behind Cisco's email security appliances. Look up your IP or domain and it gives an email reputation of Good, Neutral or Poor. Poor gets your mail throttled or refused by organisations running Cisco gear, which is many large companies and few consumer mailboxes. A dispute goes through the Talos support site linked from the result.

Your DMARC reports show what receivers did

Every dashboard above is somebody else's summary. The raw record of what receivers did with your mail is in the DMARC aggregate reports they send you daily, if your DMARC record asks for them. Each report lists the servers that sent as your domain, whether each passed, and the disposition the receiver applied: delivered, quarantined or rejected.

That's where reputation problems show first, as a source that used to pass and now doesn't, or a server you've never heard of sending under your name. Reading a report by hand shows the rows. Our weekly digest reads every report that arrives and lists each sender and its result, and on a paid plan we email you the day an unfamiliar sender first fails. Your first domain is free.

What moves a reputation

Every receiver weighs the same few things, in roughly this order.

• Spam reports. Users clicking the button. Nothing else counts as much. Send only to people who asked, and make unsubscribing one click.
• Authentication. SPF or DKIM passing and aligned with your From domain, and a DMARC record. Failing this makes every other signal worse. DMARC setup is the order to do it in.
• Bounces. Sending to addresses that don't exist, repeatedly, reads as a bought list.
• Spam traps. Addresses that never signed up for anything. Hitting them is the same signal as the bounces, with a faster listing.
• Volume swings. A domain that sends fifty a day and then fifty thousand looks like a compromised account, because it usually is.

A reputation recovers the same way it fell: with weeks of clean traffic after the cause is fixed. There's no form for it, at Google or anywhere. The blocklists are the exception, and the two guides linked above cover them.

DomainCanary is a DMARC monitoring service that turns your domain's aggregate reports into one weekly email.