---
title: "SMTP 5.7.x policy rejection: what it means - Emvero"
description: "An SMTP policy rejection can concern the sender or access to a recipient. Learn what 5.7.x means and why it does not prove that a mailbox is missing."
url: https://emvero.io/glossary/policy-rejection/
language: en
updated: 2026-10-07
---

All terms

Glossary

# Policy rejection

An SMTP policy rejection refuses an attempt under the receiving server’s rules. The restriction may concern the source, envelope sender or recipient, without proving that the mailbox is absent.

## What a policy refusal establishes

A receiving server can restrict which sources may send to a destination. The enhanced status family `5.7.x` covers security and policy conditions. For example, 5.7.1 can describe filtering by sending host or recipient, as explained in [RFC 3463](https://www.rfc-editor.org/rfc/rfc3463.html#section-3.8). A permanent refusal of this operation cannot establish that the mailbox is absent.

## Why the command stage matters

`SMTP_POLICY_REJECTED` can record a policy refusal at the recipient step. The server has heard the address and declined this attempt under its rules. It may still accept a message from another sender.

`SMTP_SENDER_REJECTED` concerns the envelope sender, before Emvero asks about the recipient. `SMTP_EGRESS_REPUTATION_REJECTED` identifies a policy or reputation refusal at that sender stage. Both concern Emvero’s attempt; neither measures your sending reputation. The [SMTP handshake explanation](https://emvero.io/glossary/smtp-handshake/) sets out the command order.

## Using the result in your workflow

If no other evidence determines the decision, the refusal returns `unknown` with `allow_with_email_confirmation`. For a product that requires mailbox control, have your application send confirmation and enforce that requirement. The policy reply alone cannot justify calling the address nonexistent.

A queue failure or a probe omitted by Emvero has a different cause from a remote refusal. The explanation of [service-side verification limits](https://emvero.io/glossary/our-own-failures/) covers those cases. Read the status, recommended action and reasons together, using the [verification result guide](https://emvero.io/blog/reading-a-verification-result/). A refusal or a positive probe describes the observed attempt and cannot predict every future delivery outcome.

## Related reason codes

The API uses these identifiers to explain a check. The notes identify values that the current verification policy or probe does not return.

`SMTP_POLICY_REJECTED`

SMTP attempt refused under destination policy

`SMTP_SENDER_REJECTED`

Envelope sender refused before the recipient check

`SMTP_EGRESS_REPUTATION_REJECTED`

Envelope sender refused under policy or reputation rules

## Related terms

### Ambiguous rejection

A recipient refusal can hide mailbox information or reflect server policy. A permanent-looking reply need not justify rejection.

### SMTP handshake

The greeting and commands used to ask a mail server about a recipient, stopping before message content is sent.

### Codes that describe us, not the address

Service protections, capacity limits or incomplete work can prevent a probe. These codes explain the check, rather than the mailbox.

## Compared side by side

### Unknown vs undeliverable

Separate inconclusive evidence from a permanent technical failure, then choose whether to retry, confirm or reject.

[All terms](https://emvero.io/glossary/)

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