Google Postmaster Tools shows how Gmail sees your mail: spam rate, authentication results, encryption and delivery errors, and in the classic view your domain and IP reputation. It is free, takes about ten minutes to set up and is the best early warning you have for inbox problems at the largest mailbox provider. This guide covers setup and how to read each view.
The interface changes. Google updates Postmaster Tools from time to time, and your account may show newer or different dashboards from those described here. The principles hold: keep the spam rate low, authenticate everything and react quickly to errors.
Step 1: Add and verify your domain
- Open Postmaster Tools. Go to postmaster.google.com and sign in with a Google account that your team can keep using.
- Add the domain. Enter the domain that appears in your DKIM signature (d=) and, separately, your From domain if different.
- Copy the TXT record. Google shows a verification record for your DNS.
- Publish it. Add the TXT record at your DNS provider and wait for it to propagate.
- Click verify. Once verified, data starts to appear if you meet the volume and authentication conditions.
Make sure the domain is authenticated first. See the authentication guide and the bulk sender requirements.
Step 2: Know what each dashboard shows
| Dashboard | What it shows | What to look for |
|---|---|---|
| Spam rate | Share of messages users reported as spam | Below 0.10 percent, with no spikes after campaigns |
| Domain reputation | Gmail view of your domain: bad, low, medium or high (classic view) | Stays at medium or high |
| IP reputation | The same for your sending IPs (classic view) | No IP lower than the others |
| Authentication | Share of mail that passes SPF, DKIM and DMARC | Close to 100 percent |
| Encryption | Share of mail sent over TLS | Close to 100 percent |
| Delivery errors | Rejected and temporarily deferred mail by reason | No growing error categories |
| Feedback loop | Complaint data by campaign identifier, for qualifying senders | Campaigns with unusually high complaints |
Why a dashboard can be empty
| Cause | How to check | Fix |
|---|---|---|
| Not enough volume | Count daily mail to personal Gmail users | Wait until volume is consistent, and keep sending steadily |
| No aligned authentication | Inspect headers for SPF or DKIM with your domain | Sign with your own domain and align the return-path |
| Wrong domain added | Compare the verified domain with the DKIM d= value | Add the correct domain |
| Verification not complete | Status shows unverified | Check the TXT record and retry |
| Data delay | Verified within the last few days | Check again after a few days |
Step 3: Act on what you see
| Signal | Likely meaning | First action |
|---|---|---|
| Spam rate above 0.10 percent | Mail is unwanted by too many recipients | Stop sending to unengaged contacts, simplify unsubscribe and review the offending campaign |
| Spam rate spike after one send | A bad segment or list source | Pause that segment and check how it was built |
| Reputation falls from high to medium or low | A pattern of poor signals over days | Slow down, send to engaged recipients and fix the cause |
| Authentication below 100 percent | Some mail fails SPF, DKIM or DMARC | Find the sending system that fails and fix alignment |
| Rate limit errors rising | You send faster than Gmail accepts | Lower the rate and spread sends over time |
| Suspected spam errors | Content or reputation problem | Follow the spam checklist |
Use it with your own data
Postmaster Tools covers Gmail only and arrives with a delay. Combine it with your delivery log, bounce reports and webhook events. The webhooks guide shows how to stream events into your own dashboards, and the bounce code guide explains the codes you will see.
A weekly routine
- Open the spam rate chart and compare it with last week.
- Check authentication and encryption percentages.
- Open delivery errors and look for new or growing reasons.
- Check reputation views if your account shows them.
- Compare dates with your campaign calendar and note anything unusual.
- Review again the day after each large send.
Not sure what your data means? Send us a screenshot of your spam rate and delivery errors and we will help you read it.
Further reading and sources
Frequently asked questions
What is Google Postmaster Tools?
Google Postmaster Tools is a free service from Google that shows senders how their mail is treated at Gmail. It reports spam rate, authentication results, encryption and delivery errors, and in its classic view also domain and IP reputation. It is the closest thing to a direct line into Gmail filtering.
Why is my Postmaster Tools dashboard empty?
The usual reasons are too little volume to Gmail users, mail that is not authenticated with SPF or DKIM aligned to the domain you added, the wrong domain added, or data that has not yet appeared after verification. Check that the domain you verified matches the DKIM signing domain or the From domain.
Which domain should I add?
Add the domain you sign with DKIM (the d= value) and the domain in your From address. For several subdomains, adding the parent domain after verifying it can give you a combined view, and you can add the subdomains separately for detail.
What is a good spam rate?
Google recommends keeping the user-reported spam rate below 0.10 percent and never reaching 0.30 percent. Rates are measured for mail delivered to inboxes and spam folders of personal Gmail users, so small numbers can move quickly on low volume.
What do the reputation levels mean?
In the classic view, reputation is shown as bad, low, medium or high for the domain and for IPs. High and medium reputation usually reach the inbox, while low and bad often lead to spam placement or rejection. Google has been updating Postmaster Tools, so check which views your account shows.
Does Postmaster Tools show data for Google Workspace users?
The main dashboards are based on mail to personal Gmail accounts. Mail to Google Workspace domains is not fully included in the user spam rate, so the data may not match the whole of your Google audience.
What do delivery errors mean?
The delivery errors dashboard shows rejected and temporarily deferred mail by reason, such as rate limit, suspected spam or authentication. Use it together with your own delivery log and the bounce code guide to decide whether the cause is volume, reputation or setup.
How often is the data updated?
Dashboards update daily and usually lag by a day or more. Short bursts of trouble can be hidden by daily averages, so keep your own near real-time monitoring of bounces and complaints as well.
Does Postmaster Tools cover Yahoo or Outlook?
No. It shows data about Gmail only. Yahoo and Microsoft have their own sender programmes and feedback loops, and you should register for those as well.
How do I improve a poor Gmail reputation?
Authenticate every message, send only to engaged recipients, remove bounces and inactive contacts, make unsubscribing simple and keep volume steady. Recovery takes weeks of clean sending, and results show in the spam rate first.