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.
What SendGrid handles#
Most platforms, including SendGrid, generate the records or settings you need under a domain authentication or sending settings page, and expose bounce and complaint data in reports. Confirm the exact location in SendGrid's current documentation.
What you still own#
- 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.
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 SendGrid set up complaint feedback loops automatically?
SendGrid provides the values and some checks, but publishing DNS, aligning domains, and monitoring results remain your responsibility.