# IP reputation

> The sending history and risk signals mailbox providers associate with an IP address.

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

## Definition

IP reputation is the receiver’s view of traffic originating from a sending IP. Providers can consider volume, complaint rate, invalid recipients, spam-trap activity, authentication, consistency, and evidence of compromise.

A shared IP carries traffic from several customers, while a dedicated IP is controlled by one sender. Dedicated does not automatically mean better: it also means the sender must create and maintain enough clean, steady traffic to establish useful history.

## Why it matters

The IP is visible at the SMTP connection, before the receiver evaluates much of the message. Poor IP history can lead to throttling or blocking, but domain and recipient-level reputation remain important too.

## How it works

1. The receiver observes the connecting IP and reverse DNS.
2. It compares current traffic with the IP’s history and expected volume pattern.
3. It combines IP signals with authenticated domains and message-level evidence.
4. It decides whether to accept, defer, reject, or subject the message to additional filtering.


## Common mistakes

- Buying a dedicated IP before sending enough consistent volume to operate one.
- Warming an IP with unengaged or old contacts.
- Assuming an IP lookup can explain every domain-specific delivery problem.
- Moving traffic abruptly between infrastructure without monitoring receiver response.

## Key takeaways

- A dedicated IP gives control and responsibility, not automatic trust.
- Stable, wanted volume is the foundation of healthy IP history.
- Always evaluate IP and domain reputation together.

## Related definitions

- [Sender reputation](https://emailbump.com/glossary/sender-reputation.md) — A receiver-specific assessment of sending identity and behavior used when filtering 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.
- [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.
- [Soft bounce](https://emailbump.com/glossary/soft-bounce.md) — A temporary delivery failure that may succeed when retried under a controlled policy.

## 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.
- [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: Email sender guidelines](https://support.google.com/mail/answer/81126?hl=en)