What Google Postmaster Tools Tells You About Your Deliverability
Google Postmaster Tools is the single most important free tool for monitoring your cold email deliverability with Gmail recipients. Here is what it shows you and how to use it.
Google Postmaster Tools is the single most important free tool for monitoring your cold email deliverability with Gmail recipients. Here is what it shows you and how to use it.
What Google Postmaster Tools is
It is a free service from Google that gives domain owners visibility into how Gmail views their email. It reports on domain reputation, IP reputation, spam rates, authentication success, and delivery errors. To access it, you verify your domain with Google by adding a DNS record.
Domain reputation
Postmaster Tools shows your domain reputation on a four-tier scale: High, Medium, Low, Bad. This is the most important metric. High means Gmail trusts your domain and your emails are likely reaching the inbox. Bad means your emails are almost certainly going to spam. Target: High or Medium. If your reputation drops to Low, investigate immediately. If it drops to Bad, stop sending and begin recovery.
Spam rate
This shows the percentage of your emails that Gmail recipients marked as spam. Google considers anything above 0.1% concerning and above 0.3% serious. Target: Below 0.1%. If you are above this, identify and fix the campaign causing complaints.
Authentication
Postmaster Tools shows the percentage of your emails that pass SPF, DKIM, and DMARC. All three should be at 100% or very close to it. Any authentication failures indicate a misconfiguration in your DNS records that needs immediate attention. Verify your setup with the SPF Checker and DMARC Checker.
Delivery errors
This section shows the percentage of your emails that were rejected by Gmail. High rejection rates indicate severe reputation or authentication issues.
How to use Postmaster Tools effectively
Check it weekly during active campaigns. Track the trends, not just the snapshots. A gradual decline in reputation from High to Medium is an early warning sign. A spike in spam rate after a new campaign launch tells you exactly which campaign to investigate. Set up Postmaster Tools for every domain you send from. It takes five minutes per domain and provides invaluable visibility into how the world's largest email provider views your sending.
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