Gmail Feedback Loop
Gmail's campaign-level feedback loop: senders tag mail with a Feedback-ID header, and Postmaster Tools reports identifiers that draw unusual spam rates from Gmail users.
What it means
Google offers the Feedback Loop to large-volume senders, and notes it is particularly useful to email service providers for detecting abuse of their services. Senders add a header called Feedback-ID made of parameters (Google calls them identifiers) that uniquely identify their campaigns. Identifiers with an unusual spam rate are reported in the Feedback Loop dashboard of Postmaster Tools.
Unlike Yahoo's and Microsoft's loops, Gmail does not send individual complaint messages: it reports aggregate spam rates per identifier, and only for @gmail.com recipients. An identifier needs a minimum number of spam reports to appear, so a quiet dashboard can mean a campaign sends very little or draws few complaints.
When the overall spam rate is high but few identifiers appear, Google suggests using fewer unique identifiers.
Example
Feedback-ID: a:b:c:SenderIdRelated terms
On this site
Sources
What this definition rests on. The wording is ours; the facts are theirs.
- Gmail Help: Feedback Loopsupport.google.com
- Gmail Help: Postmaster Tools dashboardssupport.google.com
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