22 June 2026 · 5 min read
Google Postmaster Tools (postmaster.google.com) is Google's free dashboard showing how Gmail sees the mail you send to Gmail users: whether you meet Gmail's sender requirements, how often recipients mark your mail as spam, and how much of it passes SPF, DKIM and DMARC. It complements DMARC aggregate reports. Postmaster Tools covers Gmail only and gives you domain-level totals, while DMARC reports cover every receiver that sends them and break results down by sending IP address.
Set up Postmaster Tools
From Google's setup guide:
- Sign in at
postmaster.google.com, open Manage Domains and click Add new domain. - Enter the domain you use for SPF, DKIM or both, and click Create.
- Next to the domain, open More options, choose Verify domain, and copy the TXT or CNAME record shown.
- Publish that record in your DNS, return to Postmaster Tools and click Verify. Verification is usually immediate, but the status can take up to ten minutes to update.
Once the main domain is verified, its subdomains do not need verifying again. Add a subdomain separately if you want to see its dashboards on their own, for example a marketing subdomain such as news.example.com.
Which domain to add matters. Google's Domain Reputation dashboard only counts messages sent from the exact domain used for DKIM and SPF authentication. If a platform still signs your mail with its own domain, Postmaster Tools has little to attribute to you. Setting up DKIM with your own domain, which Gmail requires of bulk senders anyway, fixes this.
The dashboards
Google's dashboard reference lists these:
| Dashboard | What it shows |
|---|---|
| Compliance status | Whether you meet Gmail's email sender requirements |
| Spam rate | The share of your messages that recipients manually mark as spam |
| IP reputation | Gmail's quality rating for your sending IP addresses |
| Domain reputation | Gmail's quality rating for your sending domains |
| Feedback loop | Campaigns that recipients marked as spam, if you send a Feedback-ID header |
| Authentication | The share of your mail passing SPF, DKIM and DMARC |
| Encryption | The share of your mail sent over TLS |
| Delivery errors | The share of authenticated mail that Gmail rejected or temporarily failed |
Data is generally updated within 24 hours but can take longer. On low-volume days, Google may leave data out to protect user privacy, so small senders often see empty charts and should rely on DMARC aggregate reports instead. Postmaster Tools does not show inbox or spam folder placement for individual messages or campaigns.
Compliance status
This dashboard checks your domain against the requirements in Gmail's email sender guidelines. It covers mail to personal Gmail accounts and shows primary domains only, although subdomain mail feeds into the result. It uses a rolling average over several days, so a fix can take up to seven days to show. Gmail, Yahoo and Microsoft DMARC requirements lists the requirements it checks.
Spam rate
The spam rate is the most important number on the dashboard. Google asks senders to keep it below 0.1% and never to let it reach 0.3%. The rate is calculated daily. Google's FAQ says a sender above 0.3% is not eligible for mitigation until the rate has stayed below 0.3% for seven consecutive days.
A rising spam rate is almost always about who you are mailing, not your DNS. Check what you sent shortly before the rise, stop mailing the segment that caused it, and make sure one-click unsubscribe works: if unsubscribing is harder than clicking Report spam, recipients will use the spam button.
Authentication
This dashboard shows the share of your mail to Gmail that passed SPF, DKIM and DMARC. Each should be close to 100% for mail you send.
- DKIM below 100%: a sending service is not signing, or signs with a key Gmail cannot find. Check the selector with the DKIM checker.
- SPF below 100%: a sender is missing from your SPF record, or the record needs more than ten DNS lookups and fails with a permanent error. The SPF checker counts the lookups.
- DMARC lower than SPF and DKIM: an alignment problem. SPF or DKIM passes, but for a domain that does not match your From address. Why DMARC fails when SPF and DKIM pass explains how to find it.
Postmaster Tools cannot tell you which source is failing. Your DMARC aggregate reports can: the DMARC report analyser shows each sending source and whether it aligned. Forwarded mail also appears in these figures, so a small shortfall is not always a configuration fault.
Encryption and delivery errors
The Encryption dashboard should read close to 100%, because Gmail requires all senders to use TLS. A lower figure points to a server or relay sending without TLS.
The Delivery errors dashboard shows the reasons Gmail rejected or deferred your authenticated mail. Short bursts of rate limiting during a large send can clear on their own. Persistent rejections usually go with a high spam rate or failing authentication, and need those fixed first. If you meet the sender guidelines and legitimate mail is still being rejected or marked as spam, verified domain owners can report a delivery issue from Postmaster Tools.
Reputation dashboards are being retired
Google has announced that the legacy Postmaster Tools interface will be replaced by Postmaster Tools v2, and that the Domain reputation and IP reputation dashboards will be retired in the process. Google says reputation data is hard for most senders to act on, reflects changes slowly, and is only one of many factors in deliverability. The deprecation has been postponed and Google has not given a date, but it is not worth building your monitoring around the reputation charts. Use spam rate, compliance status and authentication instead.
A weekly routine
- Spam rate: below 0.1%? If not, look at what you sent and to whom.
- Compliance status: any requirement marked as needing work?
- Authentication: SPF, DKIM and DMARC close to 100%? If not, use your DMARC reports to find the source.
Postmaster Tools only diagnoses; the fixes happen in your DNS and your sending lists. To check your published records now, run the DMARC checker. If you want your aggregate reports turned into per-source pass rates with alerts, DMARC analytics does that across every receiver, not just Gmail.