How do you set up and read Google Postmaster Tools?

Google Postmaster Tools is the only window Gmail gives senders into how it sees their mail. It's free, it takes a few minutes to set up, and it answers questions no outside checker can: what share of your mail Gmail users report as spam, whether Gmail thinks you meet its sender requirements, and why messages were rejected.

This guide covers setup, then each dashboard in turn, with the action to take when a number looks wrong. Everything here comes from Google's own Postmaster Tools help pages.

What is Google Postmaster Tools?

Google describes it as a service that gives senders "data and diagnostics about your email, including delivery errors, spam reports, and feedback loops" (Gmail Help). Google's Email sender guidelines tell senders to "Use Postmaster Tools to get information about the email you send to Gmail users," and measure the spam rate requirement with it.

Know its limits before you rely on it:

• Personal Gmail only. Data covers mail to @gmail.com and @googlemail.com addresses (Gmail Help). Mail to Google Workspace businesses isn't included.
• Not real time. Google says data "is updated within 24 hours but can take longer" and uses UTC (Gmail Help).
• Volume matters. "To protect the privacy of Gmail users, dashboards might not include all data on days when your outgoing email volume is low."
• Authenticated mail only. Dashboards are built from authenticated mail, and some (such as Spam rate) count only DKIM-authenticated messages.

How do you set up Google Postmaster Tools?

Google's steps, as of its current help page (Gmail Help):

Step 1: Add your domain

1. Go to the Manage Domains page at postmaster.google.com/v2/manage_domains and sign in with a Google or Google Workspace account.
2. Select Add new domain at the top right.
3. Enter the domain and select Create.

Which domain? Google says: "Add either the DKIM (d=) domain or the SPF (Return-Path) domain." For most small businesses that's simply your main domain, as long as your mail is DKIM-signed with it. If a newsletter tool signs with its own domain, set up DKIM with yours first; our DKIM records by provider pages show how for common services.

Step 2: Verify the domain

1. On Manage Domains, select More options next to the domain, then Verify domain.
2. Copy the TXT or CNAME record from the Verify ownership of domain window.
3. Add it at your DNS host. Our guides for Cloudflare, GoDaddy and Namecheap show the screens.
4. Return to Postmaster Tools and select Verify.

Google says verification is usually immediate but "it can take up to 10 minutes before your domain's verification status is updated." You can select Not now and verify later, but no data appears until you do.

Step 3: Add colleagues (optional)

1. Select More options next to the verified domain, then Manage users.
2. Select New user, enter their Google email address and select Add.

Google doesn't notify people you add, so tell them yourself.

What dashboards does Postmaster Tools have?

Use the menus at the top to pick a verified domain, a dashboard and a time range of the last 7, 30, 60, 90 or 120 days (Gmail Help).

How do you read the Compliance status dashboard?

This is the newest dashboard and the most direct answer to "does Gmail think we follow the rules?" It checks the requirements in Google's sender guidelines:

• All senders: SPF and DKIM authentication, DNS records, message formatting, encryption and user-reported spam rate.
• Bulk senders only (Google defines these as sending "about 5,000 messages or more to Gmail accounts in a 24-hour period"): DMARC authentication, one-click unsubscribe and honor-unsubscribe.

Each requirement shows one of three states:

Three things Google points out. First, after a fix "it can take up to 7 days for changes to be reflected," because the dashboard uses a rolling average. Second, DNS results reflect "the settings observed when those emails are received, not your current configuration," so check your live records with our SPF Checker, DMARC Checker and PTR Lookup rather than waiting. Third, the dashboard reports on your primary domain only, using data from its subdomains too.

Under Compliance status you'll also find Deliverability analysis, which gives a recommendation when you send too little mail, messages fail, you exceed the spam threshold, recipients don't engage, or you don't meet the guidelines.

What fixes each "Needs work" item?

• SPF and DKIM authentication: publish SPF, turn on DKIM for every sending service with your domain. See DKIM setup for Microsoft 365 and Google Workspace.
• DNS records: Google's guidelines require "valid forward and reverse DNS records, also referred to as PTR records" for sending IPs. See reverse DNS for mail servers.
• Encryption: send over TLS.
• DMARC: publish a record; Google says the policy can be none. Our DMARC Record Generator builds one.
• One-click unsubscribe: add the List-Unsubscribe and List-Unsubscribe-Post headers. See one-click unsubscribe (RFC 8058).
• Honor-unsubscribe: Google says this can show Needs work if you don't honor unsubscribe requests within 48 hours.

How do you read the Spam rate dashboard?

Google defines it as the percent of messages "delivered to engaged recipient's Inbox and then marked as spam by the recipient," for DKIM-authenticated mail (Gmail Help). The sender guidelines say to keep it "below 0.10% and avoid ever reaching a spam rate of 0.30% or higher" (Gmail Help).

Read it with care. It counts only what users report from the inbox, not what Gmail filters automatically. So Google warns that a very low or suddenly zero rate can mean Gmail is already sending much of your mail to spam, and recipients never see it to report it.

If the rate is high, Google's advice is to send only to people who opted in, confirm addresses before subscribing them, unsubscribe people who don't engage, and make unsubscribing easy. After changes, Google says to wait up to 7 days. Our guide to the spam complaint rate goes deeper.

How do you read the Authentication dashboard?

It shows the percent of your mail passing SPF, DKIM and DMARC. Google says senders "typically achieve 95% or higher success rates for DKIM and DMARC when these methods are set up correctly," while SPF tends to be lower because of third-party senders and forwarding.

What to do with low numbers, per Google:

• Low DKIM: check that your DKIM record is formatted correctly and has the right key. Forwarding by recipients can also lower it. Test with our DKIM Checker.
• Low SPF: check the record's format and that it lists every sender. Make sure third-party senders authenticate with their own domain for SPF.
• Low DMARC: a message that fails both SPF and DKIM fails DMARC. Read your DMARC aggregate reports, for example in our DMARC Report Analyzer, to find the source.

Google also recommends that every third-party sending service use DKIM for your domain with its own key.

How do you read the Delivery errors dashboard?

It shows the percent of authenticated messages Gmail rejected or deferred, with a reason for each. The most common ones and Google's recommended action:

Our Blacklist Checker and PTR Lookup help with the last two. If failure rates are higher than your own logs show, Google says forwarding or a DKIM replay attack may be the reason.

What happened to IP and Domain Reputation?

Postmaster Tools has moved to a new interface at postmaster.google.com/v2/. Google says most dashboards carry over and the new version adds Compliance status, but "the Domain and IP Reputation dashboards" will be retired, and the reputation view "is being replaced with a new, more intuitive version" (Gmail Help). Google hasn't given a firm date for retiring the old interface. Don't build processes around the reputation ratings; use spam rate, authentication and delivery errors.

If you pull data into your own reports, Google offers a Postmaster Tools API, and says integrations built on v1 must move to v2.

Next steps

1. Add and verify your domain at Postmaster Tools today, even if you send little bulk mail.
2. Fix your records first: run the Email Health Check, then the SPF Checker and DMARC Checker.
3. Send a test through the Email Deliverability Test to confirm SPF, DKIM and DMARC pass.
4. Check Compliance status weekly, and give each fix 7 days to show.
5. If recipients see warnings on your mail, read Gmail warning banners explained.

Postmaster Tools covers mail you send. For filtering the mail you receive, see how iBlockSpam works. More guides are in running email day to day.