Where you saw it: A deliverability audit asking for your Postmaster data, or Gmail placement problems you cannot diagnose from your own reports.
Why it happens
- Not set up. It requires adding the domain and verifying ownership through DNS.
- Set up for the wrong domain. The dashboard reports on the DKIM signing domain, which is often a subdomain rather than your main one.
- Volume below Google's reporting threshold, which leaves the charts empty however correct the setup is.
- Data is delayed by a day or two, so a same-day check after a send shows nothing.
The fix, in order
Add the domain that signs your DKIM
Postmaster reports against the authenticated domain. If your platform signs with mail.yourcompany.com, add that, not the root.
Verify ownership with a TXT record
Google provides a verification string to publish in DNS. It is the same pattern as Search Console and takes minutes.
Wait for volume and for data
The dashboard needs enough daily volume to report and lags by a day or two. An empty chart after a small send is expected rather than a fault.
Read domain reputation before IP reputation
Domain reputation is the more durable signal and the harder one to repair. IP reputation matters most on dedicated infrastructure.
Watch the spam rate against 0.1%
This is the number in Google's bulk sender requirements. Anything approaching 0.3% is already costing you placement.
How to know it worked
The short version
- The dashboard shows data for your sending domain within a few days.
- Authentication charts show SPF, DKIM and DMARC passing at close to 100%.
- Spam rate reads below 0.1% and domain reputation is high or medium.
Questions people ask
How much volume does Postmaster Tools need?
Google does not publish an exact figure, and in practice it takes a few hundred messages a day before charts populate reliably. Below that, expect gaps.
Which domain should I add?
The one in the d= field of your DKIM signature, since that is what Google reports against. It is frequently a subdomain your platform created.
Does it show individual complaints?
No. Google reports aggregate rates only. For per-message complaint data you need a feedback loop, and Google does not offer one to most senders.