Google Postmaster Tools: how to see what Gmail thinks of your emails
How Gmail sees your emails is only revealed by Gmail itself – via the free Google Postmaster Tools. There you mainly see your recipients' spam complaint rate and whether you meet Google's sender requirements. For anyone who regularly sends to Gmail addresses, it's part of the basic toolkit.
What the Postmaster Tools show
The Postmaster Tools are an area in your Google account at postmaster.google.com. For every verified domain, Google shows analyses of the emails that reached Gmail users, including:
- Spam rate: share of emails that recipients themselves marked as spam.
- Compliance with sender requirements: whether your domain meets Google's requirements for SPF, DKIM, DMARC, encryption and – for newsletters – one-click unsubscribe.
- Authentication and encryption: how many emails passed SPF, DKIM and DMARC and how many were transmitted encrypted.
- Delivery errors: whether and why Gmail rejected or delayed emails.
Which views exactly are available changes from time to time. The spam rate and the status of the sender requirements are the values that matter.
Setup in four steps
- Open
postmaster.google.comand sign in with a Google account. It doesn't have to be your company's Gmail mailbox. - Add your domain – the domain in the sender address (
example.com), not that of your sending service. - Google shows you a TXT record of the form
google-site-verification=…. Create it directly on your domain. - Click “Verify”. Depending on DNS, this can take a few minutes to hours. The first data then appears with a delay of one to two days.
You can add further people, such as your agency, as users of the domain without them having to create a DNS record themselves.
The most important number: the spam rate
Google requires all senders to keep the spam rate permanently below 0.3 %; below 0.1 % is recommended. That sounds generous, but it isn't: with 10,000 emails per day, 0.3 % is already 30 complaints.
| Spam rate | Meaning |
|---|---|
| below 0.1 % | Good – no action needed |
| 0.1 % to 0.3 % | Warning sign – check content, sending frequency and recipient list |
| above 0.3 % | Gmail increasingly classifies emails as spam or rejects them |
You don't lower the spam rate with technology but with content that recipients expect: only send to confirmed addresses, weed out inactive recipients, make unsubscribing easy (a clearly visible unsubscribe link beats a click on “Spam”).
Why there's often no data
Many people are surprised by empty charts. Google only shows data above a significant daily volume to Gmail recipients, to avoid conclusions about individual people. If you only send occasional individual emails, you usually won't see anything. For newsletters and larger volumes of transactional emails, the views fill up after a few days.
Working with other tools
- Before sending: the test on the home page checks a single email technically – SPF, DKIM, DMARC, blocklists, content and unsubscribe headers.
- Ongoing: domain monitoring checks your DNS records daily and analyzes DMARC reports from all major providers, not just Gmail.
- Gmail's view: the Postmaster Tools show how Gmail users react to your emails – no external tool can measure that.
More about the requirements of Gmail, Yahoo and Outlook is in our article on the sender rules of the major providers.