What Google Postmaster Tools are#
Google Postmaster Tools is a free dashboard showing how Gmail sees your domain: spam rate, domain and IP reputation, authentication pass rates, encryption, and delivery errors, for senders with meaningful volume.
Why it matters#
It is the only direct view into Gmail's opinion of your mail, and Gmail is usually the largest share of any consumer list.
Getting started#
- Add your sending domain and verify with a TXT record.
- Send consistently for a few days so data appears.
- Check spam rate daily; stay under 0.1% and never above 0.3%.
- Investigate any day domain reputation drops from High.
- Correlate authentication failures with new sending sources.
Common mistakes#
- Verifying the root domain but sending from an unverified subdomain.
- Reading reputation as a single day rather than a trend.
Frequently asked questions#
Why is Postmaster Tools empty?
Volume is too low for Gmail to report, the domain is not verified, or you are looking at the wrong domain (From versus DKIM d=).