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.
What good looks like#
- Done: Add your sending domain and verify with a TXT record.
- Done: Send consistently for a few days so data appears.
- Done: Check spam rate daily; stay under 0.1% and never above 0.3%.
- Done: Investigate any day domain reputation drops from High.
- Done: Correlate authentication failures with new sending sources.
What bad looks like#
- Seen in audits: Verifying the root domain but sending from an unverified subdomain.
- Seen in audits: Reading reputation as a single day rather than a trend.
How to move from bad to good#
Work through the good list in order and re-verify after each change. Most teams find one or two items from the bad list already present; fixing those usually produces the largest improvement.
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=).