Glossary
Spam complaint rate
Also called complaint rate, abuse rate.
Last reviewed 18 September 2026
What is a good spam complaint rate?
A spam complaint rate is the count of people who pressed the spam or junk button divided by the mail delivered to that provider over a window it chooses, and Google and Yahoo both name 0.3 per cent as the level to stay under and 0.1 per cent as the level to aim at.
The gap between the two figures is not fussiness. The higher one is where filtering starts to be applied to you, and the lower one is the headroom that means a single bad send does not take you across it.
Because these are rates they behave worse the smaller you are: at a thousand delivered messages three complaints is already 0.3 per cent, and at two hundred a single complaint is 0.5 per cent. A small sender has no statistical cushion, only a structural one.
Complaints are not really about content. Somebody presses the button when they do not recognise the sender, cannot find a way out, or are surprised by what arrived, which points at an address added without its owner asking, a long gap before the first send, a frequency nobody promised, and an unsubscribe that is hidden, slow or broken.
See also
- Feedback loop
A feedback loop is an arrangement in which a mailbox provider reports back to a sender the messages its users marked as spam, so that those addresses can be suppressed immediately rather than mailed again.
- Unsubscribe
An unsubscribe is a reader withdrawing permission to be mailed, and since February 2024 Google and Yahoo have required one to be honoured within two days, a much shorter clock than the 10 business days the United States CAN-SPAM Act allows.
- Sender reputation
Sender reputation is what a mailbox provider has learned about the domain and the infrastructure your mail comes from, assembled from complaints, bounces, spam trap hits and how the people who receive your mail behave, and it is what decides the folder.
- Confirmed opt-in
Confirmed opt-in, usually called double opt-in, is the practice of sending one message to a newly submitted address and adding it to a list only after somebody clicks the link in that message.
Read next
This term is covered properly in Email deliverability for small senders: authentication and reputation, which is a longer piece on the subject.
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