Spam Complaint Rate
01 Definition
Spam Complaint Rate meaning: The percentage of delivered emails that recipients report as spam.
Spam complaint rate is the share of delivered messages that recipients mark as spam, calculated as complaints divided by delivered emails, times 100. Mailbox providers treat it as a key trust signal. Gmail, for example, asks bulk senders to stay below 0.3 percent, and rates above that can push mail to spam.
Also called
Why it matters
How Spam Complaint Rate fits the work
Complaint rate is one of the strongest signals mailbox providers use to decide inbox placement, so keeping it low is central to staying deliverable.
In context
With 15 complaints across 30,000 delivered emails, the complaint rate was 0.05 percent, well under Gmail's 0.3 percent guideline.
Practical note
You only see complaints for providers that offer feedback loops, so your true complaint rate may be higher than reported; treat the visible number as a floor.