Microsoft weights sender reputation via SNDS and JMRP, and rejects unauthenticated bulk mail to consumer Outlook.com addresses.
What complaint feedback loops are#
Feedback loops (FBLs) are programs run by mailbox providers (Microsoft JMRP, Yahoo CFL, Comcast, and others) that send you a copy or notice whenever a recipient marks your message as spam.
Why it matters#
Complaints are the strongest negative signal. FBLs let you suppress complainers immediately and detect problem campaigns before reputation collapses.
Setting up complaint feedback loops for Outlook and Microsoft 365#
- Register your sending IPs and domains with each provider's FBL.
- Route FBL messages to an automated parser.
- Suppress every complainer from all future marketing.
- Report complaint rate per campaign and per acquisition source.
How Outlook and Microsoft 365 reports results#
Open a delivered test message in Outlook and Microsoft 365 and view the original or headers. Look for Authentication-Results and any provider-specific verdict headers. Use the provider's sender dashboard for aggregate reputation.
Common mistakes#
- Registering but never processing the reports.
- Gmail has no traditional FBL; use Postmaster Tools spam rate instead.
Frequently asked questions#
Does Gmail offer a feedback loop?
Only an aggregate one via Postmaster Tools using the Feedback-ID header. Gmail does not return individual complaints.
Does Outlook and Microsoft 365 require complaint feedback loops?
Microsoft weights sender reputation via SNDS and JMRP, and rejects unauthenticated bulk mail to consumer Outlook.com addresses. Treat complaint feedback loops as required for any meaningful volume.