Postmaster Tools reports by domain and covers Gmail; SNDS reports by IP and covers Outlook.com. Enterprise senders need both.
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.
How Microsoft SNDS differs#
Microsoft SNDS solves an adjacent problem. Postmaster Tools reports by domain and covers Gmail; SNDS reports by IP and covers Outlook.com. Enterprise senders need both. In practice the two are deployed together and monitored with the same reporting.
Which to implement first#
Start with whichever your sending platform makes easiest, then add the other. Deployment order matters less than reaching a state where both pass and align with your From domain.
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=).