How to set up Google Postmaster Tools, and listen to every other inbox too

Every time someone opens your email, clicks a link or replies, the inbox takes note. Every time someone hits "Report spam", it takes note of that too. Mailbox providers are constantly forming an opinion of you as a sender, and that opinion decides whether your next campaign lands in the inbox or the junk folder.

The good news is that the biggest providers will share some of that opinion with you, for free. Google Postmaster Tools is the best known, but Microsoft and Yahoo run their own versions. This guide walks you through setting up Google Postmaster Tools, then shows you what the other inbox feedback loops offer and how to use all of it to protect your email deliverability.

Because engagement is a conversation, and a conversation only works if you are listening to both sides.

What is an email feedback loop?

An email feedback loop is a channel a mailbox provider uses to tell senders how recipients are reacting to their mail, most importantly when someone marks a message as spam. They come in two flavours:

• Aggregate dashboards. You see trends: your spam complaint rate, authentication results and delivery errors, but not who complained. Google works this way, for privacy reasons.
• Per-message complaint reports. The provider sends back a report each time someone flags your email, so the sender can stop mailing that person. Yahoo and Microsoft both offer this.

You want both. The dashboard tells you whether something is going wrong. The per-message reports make sure someone who has clearly said "not for me" never hears from you again.

Setting up Google Postmaster Tools, step by step

Google Postmaster Tools shows you how Gmail sees the mail you send to personal Gmail addresses. Setup takes about ten minutes, plus however long your DNS takes to update. Google's own Postmaster Tools setup guide has the official steps if you want them open alongside ours.

Let's follow Lindiwe, who runs marketing for a homeware brand called Lumen & Oak. Her website is lumenandoak.com and her campaigns go out from news.lumenandoak.com.

1. Check your authentication first. Postmaster Tools reports on mail that is authenticated with your own domain, so SPF, DKIM and DMARC need to be in place on your sending domain before the data means anything. If you haven't done this yet, our guide to verifying your domain in Mail Blaze takes you through it, and our support team can check it with you.
2. Sign in. Go to postmaster.google.com and sign in with any Google account. A shared team account is a good idea, so access does not live in one person's inbox.
3. Add your root domain. Click to add a domain and enter your root domain, lumenandoak.com in Lindiwe's case, rather than the subdomain. Verifying the root first means you can add subdomains later without extra DNS records.
4. Copy the verification record. Google gives you a TXT record. Copy it exactly.
5. Add it to your DNS. Log in wherever your domain's DNS is managed (your domain registrar or hosting provider) and add the TXT record to the root domain.
6. Verify. Give DNS a little time to update, then return to Postmaster Tools and click Verify. If it fails and you are sure the record is right, wait a while and try again. Google also offers a CNAME option if the TXT route keeps failing.
7. Add your sending subdomains. Once the root is verified, add each subdomain you actually send from, such as news.lumenandoak.com. Each one gets its own view, which helps you separate newsletters from, say, order confirmations.
8. Share access. Add colleagues who need to see the data from the domain's user management settings. You can only add users to a verified domain.

Then, be patient. A newly verified domain can show empty dashboards for days. Google only displays data once it has seen enough authenticated mail from you to personal Gmail accounts, so low-volume senders may see gaps.

What Google Postmaster Tools tells you now

If you used Postmaster Tools a few years ago, it looks different today. Google retired the original version in favour of v2, and the old Domain Reputation and IP Reputation scores are gone. In their place is a view built around Gmail's sender requirements. Three areas matter most:

• Compliance status. A pass or fail check against Gmail's rules: SPF and DKIM authentication, DMARC, alignment between your From address and your authenticated domain, encrypted delivery, and whether you handle unsubscribes correctly. Anything failing here is your first job.
• Spam rate. The share of your mail that Gmail users reported as spam. Google recommends staying below 0.1%, and treats 0.3% as a policy violation. That is three complaints in every thousand delivered emails, so it does not take much.
• Deliverability analysis. Added in June 2026, this section turns your data into a plain-language verdict. It might tell you recipients are responding well, that you have not sent enough Gmail traffic to judge, that you are not compliant, or that recipients are reacting negatively. If you only read one thing, read this.

Two things to remember. Postmaster Tools is not real time, so it will not explain this morning's send. And it shows trends, not names, so it will never tell you which subscribers complained. That is where the other feedback loops come in.

Microsoft: SNDS and JMRP

Microsoft's consumer mailboxes (Outlook.com, Hotmail, Live and MSN addresses) have two free sender services, now managed from one place, the SNDS portal, which moved to a new address in June 2026:

• SNDS (Smart Network Data Services) reports how Outlook.com rates mail from specific sending IP addresses: a green, yellow or red filter result, complaint rate and volume, per IP, per day.
• JMRP (Junk Mail Reporting Program) sends a report each time an Outlook.com user marks a message as junk, so the sender can stop mailing that person. Since 2026 these reports carry the message headers only, not the full email.

The catch is that both are built around IP addresses, not domains. To register, you have to prove you control the sending IPs. If you send through an email marketing platform on shared IP addresses, those IPs belong to the platform, so this is usually something your platform manages rather than something you set up yourself.

Two other points worth knowing. SNDS covers consumer Outlook.com addresses only, so it tells you nothing about business recipients on Microsoft 365. And Microsoft requires anyone sending more than 5,000 messages a day to its consumer mailboxes to pass SPF, DKIM and DMARC. Mail that falls short can be rejected outright, not just sent to junk.

Yahoo and AOL: Sender Hub and the Complaint Feedback Loop

Yahoo brings everything for senders together in Yahoo Sender Hub, which covers both Yahoo Mail and AOL. The old Yahoo postmaster sign-up forms are gone, so Sender Hub is the only route in.

Its main service is the Complaint Feedback Loop (CFL). When a Yahoo or AOL user reports your email as spam, Yahoo sends back a report on that message. Unlike Microsoft's programme, it is domain based: it works on the domain that signs your mail with DKIM, so mail that is not DKIM-signed with your domain will not be covered.

Yahoo's Complaint Feedback Loop page has the official steps and the sign-up link. In short:

1. Create a Sender Hub profile.
2. Add your DKIM signing domain and verify it with the DNS record Yahoo gives you.
3. Go to Manage Services, choose Complaint Feedback Loop, enrol the verified domain and add the mailbox where reports should go.

Sender Hub also has an Insights view with aggregate figures for verified domains, including delivered volume and spam complaint rate. Yahoo's sender requirements ask senders to keep complaints below 0.3%.

One word of caution. Complaint reports are only useful if someone acts on them. If reports land in a mailbox nobody reads, the people who complained keep receiving your email and your reputation keeps sliding. Talk to us before you enrol so we can agree how complaints are handled on your account.

The inbox feedback loops at a glance

Turning feedback into better email deliverability

Data only helps if it changes what you send next. Here is how to put these signals to work.

• Make it a habit. Check Postmaster Tools at least once a month, and a few days after any unusually large send. Trends matter more than any single day.
• Fix compliance first. A failing authentication or unsubscribe check undermines everything else. If something is red and you are not sure why, call or chat to our support team, seven days a week.
• Find the send behind a spike. If your spam rate jumps, use the comparative filters in your Mail Blaze reporting to compare that campaign with your usual ones. Look at the audience, the subject line and how long since that segment last heard from you.
• Keep your list healthy. Our List Health Check scans every list you upload and tells you whether it needs cleaning. Addresses removed in cleaning move to a quarantined status rather than being deleted, so the data stays yours.
• Make leaving easy. Someone who cannot find the unsubscribe link will find the spam button instead. A visible unsubscribe link protects your reputation.
• Send what people signed up for. Most complaints come from people who no longer recognise you or no longer want what you send. Relevance is the best complaint prevention there is.

Frequently asked questions

Is Google Postmaster Tools free? Yes. So are Microsoft SNDS, JMRP and Yahoo Sender Hub.

Why does Google Postmaster Tools show no data? Usually because Gmail has not yet seen enough authenticated mail from your domain to personal Gmail accounts. Check you verified the domain your mail is actually authenticated with, then give it time.

Where has my domain reputation score gone? Google removed the Domain Reputation and IP Reputation dashboards when it moved everyone to Postmaster Tools v2. The Compliance status page and Deliverability analysis verdict now do that job.

What is a good spam complaint rate? Google recommends staying below 0.1% and treats 0.3% as a violation. Yahoo also uses 0.3% as its threshold. Lower is always better.

Does Gmail tell me who reported my email as spam? No. Gmail only shares aggregate figures. Yahoo and Microsoft send per-message complaint reports.

Do I need SNDS if I send on shared IP addresses? You generally cannot register shared IPs yourself, because you do not control them. Your sending platform looks after that side.