# Sender reputation

> A receiver-specific assessment of sending identity and behavior used when filtering email.

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

## Definition

Sender reputation is the history mailbox providers associate with signals such as a sending domain, DKIM domain, IP address, message stream, or combinations of those identities. It is better understood as a changing set of private receiver models than as one portable score.

Positive history is built through wanted, authenticated, consistent mail. Complaints, unknown users, spam-trap hits, suspicious traffic, erratic volume, and compromised infrastructure can weaken it.

## Why it matters

Reputation influences whether providers accept, defer, reject, or filter mail. It also explains why two senders using identical templates and infrastructure can receive different outcomes.

## How it works

1. Receivers identify the sending IP and authenticated domains.
2. They combine recent and historical traffic, complaint, bounce, engagement, and abuse signals.
3. Models can evaluate each stream and mailbox relationship differently.
4. Reputation changes as new behavior replaces or reinforces prior history.


## Common mistakes

- Searching for one global reputation score.
- Believing a new IP or domain erases poor sending practices.
- Mixing transactional and promotional traffic so one stream can damage the other.
- Reacting to normal daily variation instead of sustained receiver-specific trends.

## Key takeaways

- Reputation belongs to receivers, not senders.
- Domains, IPs, streams, and recipient relationships all contribute.
- Healthy acquisition and low complaints are the strongest long-term controls.

## Related definitions

- [IP reputation](https://emailbump.com/glossary/ip-reputation.md) — The sending history and risk signals mailbox providers associate with an IP address.
- [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.
- [Email blocklist](https://emailbump.com/glossary/email-blocklist.md) — A published or private dataset of IPs or domains associated with unwanted or risky email.
- [Spam complaint](https://emailbump.com/glossary/spam-complaint.md) — A recipient signal that a message is unwanted, usually created by marking it as spam or junk.

## Related guides

- [How to A/B test email service providers without fooling yourself](https://emailbump.com/blog/ab-test-email-service-providers.md) — A rigorous guide to ESP evaluation: experimental design, reputation confounders, delivery and latency metrics, webhook reliability, failover, cost, and migration.
- [Gmail reputation-based bounces: diagnose, contain, and recover](https://emailbump.com/blog/gmail-reputation-bounces.md) — An incident guide to Gmail 4.7.x and 5.7.x responses, sender-level classification, safe retries, Postmaster Tools, abuse containment, and reputation recovery.
- [How to check your email domain reputation—and improve it](https://emailbump.com/blog/check-email-domain-reputation.md) — A practical guide to authenticated sending domains, Google Postmaster Tools, reputation signals, investigation workflows, stream separation, and recovery.
- [Email bounces: how to classify, retry, suppress, and recover](https://emailbump.com/blog/email-bounce-handling-guide.md) — A practical operating guide to SMTP failures, enhanced status codes, retries, suppression, webhooks, and the product workflows that protect sender reputation.
- [How to check your sending IP reputation in 2026](https://emailbump.com/blog/check-sending-ip-reputation.md) — A practical audit for finding your real sending IPs, reading receiver-specific signals, and fixing the behavior behind a reputation problem.
- [Email blocklists and RBL removal in 2026: a practical guide](https://emailbump.com/blog/email-blocklists-guide.md) — Verify an IP or domain RBL listing, connect it to real SMTP failures, fix the cause, and use the blocklist operator's official removal process.

## Primary sources

- [Google: Top sender issues](https://support.google.com/mail/answer/15256272?hl=en)