What Postmaster Tools can and cannot tell you
Postmaster Tools reports on email you send to personal Gmail accounts, meaning addresses ending in @gmail.com or @googlemail.com. You need a Google Account or Google Workspace account to use it. [1] It says nothing about Outlook, Yahoo or company mailboxes, so a clean Gmail picture does not prove your whole list is healthy.
The data is not real time. Google says it is typically updated within 24 hours but can take longer, every chart uses UTC, and you can view 7, 30, 60, 90 or 120 days. [2] That makes it a trend tool: use it to confirm a problem is building or fading, not to debug a send that went out an hour ago.
| Question | Can Postmaster Tools answer it? | Where to look instead |
|---|---|---|
| Are Gmail users marking my mail as spam? | Yes, as a daily percentage [2] | Spam rate dashboard |
| Do I meet Gmail sender requirements? | Yes, per requirement [2] | Compliance status dashboard |
| Did one specific message land in the inbox? | No; data is aggregated and delayed [2] | Send a test to a seed Gmail account |
| How do Outlook or Yahoo treat my mail? | No; personal Gmail only [1] | Those providers' own sender programs |
| Are my SPF, DKIM and DMARC passing at Gmail? | Yes, as pass percentages [2] | Authentication dashboard, plus your DMARC reports |
Choose the right domain before you add it
Google asks for the domain you use to authenticate outgoing email: the DKIM signing domain (d=) or the SPF Return-Path domain. If those are the same, the dashboards cover mail authenticated by SPF, DKIM or both. [1] Data is keyed to that authenticating domain, so if your email platform still signs with its own shared domain rather than yours, your own domain may show little or nothing until custom DKIM is set up.
Add the primary domain first. Google says a verified primary domain means its subdomains do not need separate verification, and recommends adding subdomains after the primary is verified. [1] If you send newsletters from a subdomain such as news.example.com, add example.com, verify it, then add news.example.com so its dashboards are available separately.
| Your setup | Add this domain | Then |
|---|---|---|
| You send from example.com with custom DKIM for example.com | example.com | Nothing else needed |
| Marketing mail signed for news.example.com, receipts for example.com | example.com | Add news.example.com; no second verification [1] |
| Platform signs with its own shared domain | Set up custom DKIM first | Then add your domain |
| Several brands on different domains | Each domain separately | Each needs its own verification record [1] |
Verify the domain step by step
Google launched the newer Postmaster Tools interface in 2024 and says the old one will be retired. [5] Verification uses a DNS record that proves you control the domain; Google offers either a TXT or a CNAME record. [1] If you click Not now you can skip verification, but no email data appears until the domain is verified. [1]
- Sign in to Postmaster Tools and click Add new domain. [1]
- Enter the authenticating domain, for example example.com. [1]
- Copy the TXT or CNAME record shown in the Verify ownership of domain window. [1]
- At your DNS host, add it to the root of the domain. In hosts that use a Host field, a root TXT record usually goes in as @; a CNAME uses the exact name Google shows, minus your domain if the host appends it.
- Return to Postmaster Tools and click Verify. Google says this usually works right away and the status can take up to 10 minutes to update. [1]
- If it fails, Google suggests waiting a few minutes, checking the string was copied exactly, or retrying with a new string. [1]
- Optional: under More options, then Manage users, add colleagues by Google email address. Google does not notify them, so tell them yourself. [1]
Why your dashboards may be empty
The most common surprise after setup is a blank dashboard. Google does not publish a minimum volume. Its setup page says data may be missing if the total number of messages sent in a day is too low, as a privacy safeguard, and the dashboards page says low-volume days may be omitted. [1] [2] A small list sending once a week should expect gaps; an empty chart on those days is not a sign of a problem.
Other reasons for missing data follow from how Google scopes each dashboard. Spam rate counts only DKIM-authenticated messages, Domain reputation counts only mail sent from the exact domain used for DKIM and SPF, and compliance status is shown for primary domains only, though subdomain data feeds the calculation. [2] If your DKIM signature uses a different domain from the one you added, the spam rate chart for your domain can stay empty even at high volume.
What each dashboard means
The dashboards below are described from Google's help page. Google also says the Domain and IP Reputation dashboards are being retired in the new interface and the reputation view replaced, because reputation data is hard to act on, changes slowly and is only one factor in delivery. [5] Build your routine around the dashboards that remain.
| Dashboard | What Google says it shows | What to do with it |
|---|---|---|
| Compliance status | Whether you meet Gmail sender requirements: Compliant, Needs work or No data found; rolling average, changes can take up to 7 days [2] | Fix any Needs work row first; recheck a week after the fix |
| Spam rate | Share of DKIM-authenticated messages reaching engaged recipients' inboxes that are then marked as spam [2] | Hold below 0.1%; investigate any day near 0.3% [3] |
| Authentication | Percent of mail passing SPF, DKIM and DMARC; properly configured senders typically reach 95% or higher for DKIM and DMARC [2] | Below 95% DKIM usually means a source sending without your signature |
| Encryption | Percent of inbound and outbound Gmail traffic over TLS [2] | Should be near 100%; TLS is a requirement for all senders [3] |
| Delivery errors | Percent of authenticated messages rejected or temporarily failed, with reasons [2] | Read the reason text; spikes after a send point to content or volume |
| Feedback loop | Spam rates per campaign ID, only after you set up Feedback Loop headers [2] | Useful for high-volume senders tagging campaigns |
| Domain and IP reputation | Bad, Low, Medium or High labels [2]; being retired [5] | Do not plan around these |
Spam-rate thresholds and the bulk sender rules
Google's sender guidelines ask every sender to keep the spam rate in Postmaster Tools below 0.3%, recommend staying below 0.10%, and say to avoid ever reaching 0.30%. [3] The FAQ adds that spam rate is calculated daily, that bulk senders above 0.3% are ineligible for mitigation while they stay there, and that eligibility returns after 7 consecutive days below 0.3%. [4]
A bulk sender is one sending about 5,000 or more messages to Gmail accounts in 24 hours. [2] The status is permanent once reached, and mail from subdomains counts toward the same primary domain: Google's example is 2,500 messages from the root domain plus 2,500 from a subdomain. [4] Bulk senders must also publish DMARC (a p=none policy is allowed), align the From domain with SPF or DKIM, and support one-click unsubscribe with a visible unsubscribe link for marketing mail. [3] The compliance dashboard flags Needs work if unsubscribe requests are not honored within 48 hours. [2]
Worked example: if 20,000 of your messages reach engaged Gmail inboxes in a day, 20 spam reports is 0.1% and 60 is 0.3%. On a smaller day of 2,000 inbox deliveries, just 6 complaints reaches 0.3%, which is why one badly targeted send to an old segment can undo weeks of clean sending.
| Rule | All senders | Bulk senders (about 5,000+ a day to Gmail) |
|---|---|---|
| Authentication | SPF or DKIM [3] | SPF and DKIM plus DMARC; p=none allowed [3] |
| From alignment | Not required | From domain must align with SPF or DKIM domain [3] |
| Spam rate | Below 0.3%; aim for under 0.1% [3] | Same; above 0.3% loses mitigation eligibility [4] |
| Unsubscribe | Not listed for all senders | One-click unsubscribe headers and a visible link [3]; honored within 48 hours [2] |
| DKIM key | 1024 bits or longer; 2048 recommended [3] | Same |
A weekly ten-minute routine
- Open Compliance status and confirm every row reads Compliant; note any Needs work row and its date. [2]
- Set the range to 30 days and scan Spam rate for any day above 0.1%. Match spikes to the campaign sent the day before.
- Check Authentication: DKIM and DMARC pass rates under 95% suggest a service sending as your domain without your signature. [2]
- Read Delivery errors reasons on any day with a spike. [2]
- If a spam spike lines up with a send to an old or purchased segment, stop mailing that segment and clean the list before the next send.
- Record the numbers in a sheet; Postmaster Tools keeps at most 120 days in view. [2]
Questions before you decide
Which domain should I add to Postmaster Tools?
Google says to add the domain you use to authenticate outgoing mail: the DKIM d= domain or the SPF Return-Path domain. Once a primary domain is verified, its subdomains can be added without separate verification.
How many emails do I need to send before data appears?
Google does not publish a number. Its setup page says data may be missing when the total messages sent in a day is too low, as a privacy safeguard, and suggests checking again once volume increases.
What spam rate is too high?
Google asks all senders to keep the Postmaster Tools spam rate below 0.3% and recommends staying below 0.1%. Bulk senders above 0.3% are ineligible for mitigation until the rate stays below 0.3% for 7 consecutive days.
Is the Domain reputation dashboard still worth watching?
Google says the Domain and IP Reputation dashboards are being retired in the new Postmaster Tools interface because reputation is hard to act on and changes slowly. Spam rate, compliance status, authentication and delivery errors are the dashboards to build a routine around.
Sources & verification
Product details and prices can change. Check the linked provider before buying.
- Google Gmail Help: Get started with Postmaster Tools Accessed 30 Oct 2026
- Google Gmail Help: Postmaster Tools dashboards Accessed 30 Oct 2026
- Google Workspace Admin Help: Email sender guidelines Accessed 30 Oct 2026
- Google Workspace Admin Help: Email sender guidelines FAQ Accessed 30 Oct 2026
- Google Gmail Help: Deprecation of the old Postmaster Tools interface Accessed 30 Oct 2026
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