# Spam complaint

> A recipient signal that a message is unwanted, usually created by marking it as spam or junk.

- **Category:** Deliverability
- **Updated:** July 2026
- **Canonical page:** [https://emailbump.com/glossary/spam-complaint](https://emailbump.com/glossary/spam-complaint)

## Definition

A spam complaint is recorded when a recipient tells a mailbox provider that a message is unwanted. Some providers return complaint data to qualified senders through feedback loops, often with the recipient identity removed or encoded.

Complaint rate is a lagging signal of permission, recognition, frequency, targeting, and expectation. A technically valid unsubscribe link does not compensate for mail recipients did not expect.

## Why it matters

Complaints are among the clearest negative signals available to mailbox providers. A small rate can have material reputation impact at scale, especially when concentrated in a stream or acquisition source.

## How it works

1. The recipient marks a message as spam.
2. The mailbox provider records the action and updates its filtering models.
3. When a feedback loop is available, a complaint report may reach the sender.
4. The sender suppresses the recipient and investigates the campaign, source, and expectation failure.


## Common mistakes

- Continuing to send to a known complainant.
- Blaming the complaint button instead of examining why the message felt unwanted.
- Looking only at overall rate instead of campaign and acquisition source.
- Using the same stream for critical product mail and high-risk promotions.

## Key takeaways

- Suppress complainants immediately.
- Investigate the expectation that failed, not only the creative.
- Monitor provider dashboards because not every complaint is returned directly.

## Related definitions

- [Sender reputation](https://emailbump.com/glossary/sender-reputation.md) — A receiver-specific assessment of sending identity and behavior used when filtering email.
- [Suppression list](https://emailbump.com/glossary/suppression-list.md) — A durable do-not-send control containing recipients or destinations that must not receive certain email.
- [List hygiene](https://emailbump.com/glossary/list-hygiene.md) — The ongoing practice of keeping audience permission, reachability, source, and engagement data trustworthy.
- [Email deliverability](https://emailbump.com/glossary/email-deliverability.md) — The ability to reach the part of the mailbox where a wanted recipient can find and act on an email.

## Related guides

- [Why customers mark transactional email as spam—and how to stop it](https://emailbump.com/blog/reduce-transactional-email-spam-complaints.md) — An operational guide to expectation, message purpose, notification controls, duplicate prevention, form abuse, suppression, and complaint monitoring.
- [Google Postmaster Tools in 2026: the dashboards that matter](https://emailbump.com/blog/google-postmaster-tools-guide.md) — A practical guide to the new compliance view, spam-rate signals, authentication data, delivery errors, feedback loops, and the Postmaster Tools v2 API.
- [The email deliverability checklist for every campaign](https://emailbump.com/blog/email-deliverability-checklist.md) — A practical pre-send routine for protecting your sender reputation and reaching more inboxes.

## Primary sources

- [Google: Spam rate dashboard](https://support.google.com/mail/answer/14668346?hl=en)