Our domain reputation says Low. How long until it recovers?

Google does not publish a recovery time. In practice it moves over weeks, not days, and only while sending stays clean and consistent. The nearest published signal is in the sender guidelines FAQ, which says bulk senders become eligible for mitigation once their spam rate stays below 0.3 percent for seven consecutive days. Treat that as the shape of the timescale rather than a promise.

Postmaster Tools shows a healthy spam rate, so why does our email still land in spam?

Because of how the rate is defined. Google counts messages delivered to an engaged recipient's inbox and then marked as spam by that recipient. Mail that Gmail already filtered into the spam folder is not counted, so a domain being filtered heavily can still show a low rate. Check the authentication dashboard and the raw headers of a filtered message instead.

Google Postmaster Tools: Setup and How to Read It

Q: Is Postmaster Tools worth setting up if we only send a few hundred emails a day?

Set it up, but do not rely on it. Google says the dashboards might not include data for a sending domain when traffic to personal Gmail accounts is too low, and its Verified Sender Program rules describe needing a sizable, consistent daily volume, at least hundreds of messages per day to unique Gmail accounts, before there is enough data to evaluate. For a smaller sender, DMARC aggregate reports are the more reliable instrument because they come from many receivers, not only Gmail.

The dashboard nobody opens until the mail starts bouncing

Say a 30-person logistics company sends quotes, delivery notices and one monthly newsletter from the same domain. Nothing goes wrong for two years. Then a client mentions they stopped seeing the delivery notices, someone checks the newsletter platform, and the Gmail open rate has quietly halved since spring.

By the time we get that call the question is always the same: is Gmail filtering us, and since when. Almost nobody can answer it, because the one place that would have shown the slope was never turned on. Google Postmaster Tools is free, costs one DNS record, and is the only view Google gives you of how Gmail treats your domain.

What it shows, and what it does not

Google's Postmaster Tools dashboards page describes it plainly: they let you view data about outgoing email you send to personal Gmail accounts, covering spam rate, reputation, message authentication and delivery errors, plus encryption and feedback loop.

Three limits are worth fixing in your head first.

Personal Gmail accounts. Mail to a client's Google Workspace mailbox is not what these graphs report on.
Nothing outside Google. Outlook, Yahoo and corporate filters are invisible here. This is one provider's opinion, not a deliverability score.
It is a mirror, not a lever. Nothing inside it improves delivery. What you fix in response lives in DNS, your sending platform, or your list.

The history window is short: the last 7, 30, 60, 90 or 120 days. A problem you notice six months late is one whose beginning you will never see, which is the argument for setting this up before anything is wrong.

Setup: pick the right domain, add one record

First, which domain to add. Google's setup page is specific: enter the domain you use to authenticate outgoing email with SPF, or DKIM, or both. If all your mail flows through one Google Workspace tenant, that is the company domain. If you use a marketing platform or an invoicing service, the signing domain is often a subdomain belonging to that platform, and that is the entry that will collect data. On a typical project we add three or four.

Second, verification. Postmaster Tools hands you a TXT or a CNAME record to add wherever your DNS is actually hosted. Google's help says verification is normally immediate and can take up to ten minutes for the status to update.

Type:  TXT
Name:  @                 (the root of the domain)
Value: (the string Postmaster Tools shows you)
TTL:   3600

The mistake we clean up most often is the record going in at the registrar while the nameservers point somewhere else. It has to live wherever the nameservers say authority is. And verification only proves ownership, it does not create data.

Why a small sender opens it and sees nothing

This is the most common outcome for the businesses we work with, and it is not a fault in your setup. Google states that to protect the privacy of Gmail users the dashboards might not include all data on days when outgoing volume is low, and that if your traffic to personal Gmail accounts is too low, they might not include your sending domain at all.

How low is low? Google does not publish a general threshold. The closest published figure sits in the eligibility rules for the Gmail Verified Sender Program, which say a sender needs a sizable, consistent daily volume, at least hundreds of messages per day to unique personal Gmail accounts, before Postmaster Tools generates sufficient data. A twelve-person accounting firm sending forty quotes a day is nowhere near that.

We still set it up, because the month the newsletter goes out the graphs appear. But we do not build the monitoring on it. For a low-volume sender the working instrument is the DMARC aggregate report, which arrives from every participating receiver rather than Gmail alone.

Domain reputation and IP reputation, read honestly

Google sorts both into four buckets. High is a good track record with a very low spam rate that complies with the sender guidelines, and its mail will rarely be marked by the spam filter. Medium sends good mail but has occasionally sent a low volume of spam. Low sends a considerable volume of spam regularly, and its mail will likely be marked as spam. Bad has a history of an enormously high volume of spam, and its mail will almost always be rejected at SMTP.

Both graphs cover DKIM-authenticated messages sent to Gmail accounts, one more reason DKIM is not optional. Without it there is nothing for Google to attribute to you.

What matters is who owns the thing being judged. If you send through Google Workspace or Microsoft 365, the sending IP belongs to your provider and is shared with enormous numbers of other tenants, so it is not yours to move. Domain reputation is. It is also slow in both directions: weeks of bad sending to degrade, weeks of good sending to recover. Nobody fixes a Low rating on a Tuesday.

Spam rate and the 0.3 percent line

Read the definition before the number. Google defines spam rate as the percent of your messages delivered to an engaged recipient's inbox and then marked as spam by that recipient, measured on DKIM-authenticated messages sent to Gmail accounts, and calculated daily.

Two consequences follow. Mail Gmail already routed to spam is not in the denominator, so the rate can look healthy while your delivery is genuinely bad. And the measure is complaints, not bounces or unsubscribes, which are different problems with different fixes.

Google publishes two thresholds that are easy to confuse. The Email sender guidelines say to keep spam rates reported in Postmaster Tools below 0.3 percent. The sender guidelines FAQ is stricter: keep it below 0.1 percent and prevent it from ever reaching 0.3 percent or higher, because rates at or above 0.3 percent have an even greater negative impact on inbox delivery. The same FAQ says bulk senders become eligible for mitigation once the spam rate stays below 0.3 percent for seven consecutive days.

Translate 0.1 percent to a small business: one complaint per thousand delivered messages. Send two thousand a month and a handful of irritated recipients puts you over. That is why we treat list hygiene, honest subject lines and a working unsubscribe as deliverability work rather than marketing preference.

The authentication view is a free SPF, DKIM and DMARC check

Google describes the Authentication dashboard as the percent of your email that passes SPF, DKIM and DMARC, for messages that carry your sending domain in the From header.

We read it as a census of who sends as you. Anything short of full pass rates means a system is sending in your name that nobody authenticated, and the shape of the gap tells you what kind. A flat line below full pass is a permanent misconfiguration, usually a platform that was never given DKIM. A sawtooth dipping on the same days each month is a scheduled job, and in Latin America very often the electronic invoicing run. If DKIM passes on 70 percent of your mail, the missing 30 percent is a real service with a real name.

Delivery errors, encryption and the feedback loop

Delivery errors graphs the percentage of your email rejected or temporarily failed against all authenticated traffic, with a list of failure reasons underneath. The list is the valuable part, not the percentage.
Encryption shows inbound and outbound TLS percentages. Google's sender guidelines list a TLS connection among the requirements for bulk senders.
Feedback loop reports the spam rate for campaign messages carrying a feedback loop identifier. If your platform does not set one, this stays empty, as it does for most small senders.

The compliance view, and the 5,000 message line

Google's documentation describes the Compliance status dashboard as available to all senders, including bulk senders, and used to verify that outgoing email meets the sender requirements in the Email sender guidelines.

The requirements it checks against are the published ones for bulk senders: SPF and DKIM for your domain, DMARC for your sending domain, valid forward and reverse DNS records (PTR) for sending domains or IPs, a TLS connection, and spam rates in Postmaster Tools below 0.3 percent. Google defines a bulk sender as anyone sending about 5,000 messages or more to Gmail accounts in a 24-hour period.

Small businesses read 5,000 a day as a line they will never reach, and then reach it for one week in November. The threshold is a 24-hour period, not an annual average, so one seasonal campaign can put a company into the bulk category with authentication never built for it. Meeting the requirements year-round is cheaper than meeting them under pressure.

What we actually do when a graph turns

An order, because doing these out of sequence wastes weeks.

Confirm the authentication first. A reputation conversation with broken DKIM wastes everyone's time.
Name every sender. Cross-read the authentication gap against DMARC aggregate reports until every system sending as the domain is identified, then authenticated or switched off.
Look at what was sent on the days the line moved. A purchased list, a re-engagement blast to addresses untouched for three years, or a new platform sending at volume without warmup is usually right at the inflection.
Cut the source of the complaints, then hold volume steady. Stop the campaign, clean the list, and send consistent, expected mail. Consistency rebuilds the record.
Wait, and measure weekly. Checking daily produces anxiety, not information.

One tool, two interfaces

Worth knowing before you build a process on any one graph. Google's help center documents a newer Postmaster Tools alongside the original, and states that the legacy web interface is being deprecated. Every dashboard carries across with one exception, the Domain and IP Reputation dashboards, which the page says will be retired. Google has not published a retirement date; the page says the deprecation was postponed after sender feedback. So build your monitoring on authentication, spam rate and compliance, and treat the reputation graph as context rather than foundation.

How Guanacos Tech helps

Most of what we do with Postmaster Tools is unglamorous. Verify it against the right domains, work out whether the client's volume will ever produce data, and build the monitoring on DMARC reports when it will not. Then the authentication view becomes the to-do list: find the systems sending unsigned mail, fix the records, watch the lines settle. If your mail started behaving differently and nobody can say when, that is the question this data was meant to answer. Book a deliverability review and we will look at it with you. Our email deliverability service covers the setup and the fixes that follow, and how we work explains the engagement.

Every figure above comes from Google's own sender documentation, checked on 16 September 2026.

Google Postmaster Tools: how to set it up and what the reputation graphs actually mean