---
title: "Email error 553"
description: "A 553 email error is normally related to SMTP authentication not being used. Most mail servers require that you authenticate with a valid user on that system, before you're allowed to relay a remote..."
url: https://www.inmotionhosting.com/support/email/email-error-553/
date: 2012-10-26
modified: 2021-08-16
author: "InMotion Hosting Contributor"
categories: ["Email", "Website Error Numbers"]
type: post
lang: en
---

# Email error 553

A **553 email error** is normally related to SMTP authentication not being used. Most mail servers require that you authenticate with a valid user on that system, before you’re allowed to relay a remote message out. However some mail administrators will also using the **553 error** if a user doesn’t exist or for various other reasons as well.

You should receive a bounce-back message from the server with a variation of **email error 553** in the subject, and the body should contain your original message that you attempted to deliver.

## Troubleshooting the Email Error 553

### Example bounce-back message

Return-path: <>
Envelope-to: **sender@example.com**
Delivery-date: Mon, 14 Nov 2011 05:13:57 -0800
Received: from mailnull by biz29.inmotionhosting.com with local (Exim 4.69)
id 1RPwMH-0008Q0-2H
for **sender@example.com**; Mon, 14 Nov 2011 05:13:57 -0800
X-Failed-Recipients: **recipient@RemoteDomain.com**
Auto-Submitted: auto-replied
From: Mail Delivery System
To: **sender@example.com**
Subject: [Mail delivery failed: returning message to sender](/support/email/mail-delivery-failed-returning-message-to-sender/)
Message-Id:
Date: Mon, 14 Nov 2011 05:13:57 -0800

This message was created automatically by mail delivery software.
A message that you sent could not be delivered to one or more of its
recipients. This is a permanent error. The following address(es) failed:

recipient@RemoteDomain.com
SMTP error from remote mail server after RCPT TO:<**recipient@RemoteDomain.com**>:
host RemoteDomain.com [123.123.123.123]:
**553 5.7.1 Not an open relay, so get lost**

—— This is a copy of the message, including all the headers. ——

Return-path: <**sender@example.com**>
Received: from chrisg6 by biz29.inmotionhosting.com with local (Exim 4.69)
(envelope-from <**sender@example.com**>)
id 1RPwMG-0008Pm-5x
for **recipient@RemoteDomain.com**; Mon, 14 Nov 2011 05:13:56 -0800
To: Recipient <**recipient@RemoteDomain.com**>
X-Autorespond: On vacation
MIME-Version: 1.0
X-Loop: “On vacation” <**recipient@RemoteDomain.com**>
Precedence: auto_reply
X-Precedence: auto_reply
From: “Sender” <**sender@example.com**>
Content-type: text/plain; charset=ansi_x3.110-1983
Subject: Email acknowledgement from Sender

>

## Common variations of the 553 email error

- 553 5.7.1 Not an open relay, so get lost
- 553 Invalid user.
- 553 message blocked, you are not authorized to send mail, authentication is required.
- 553 Null Sender is not allowed.
- 553 5.1.1 sorry, no mailbox here by that name.
- 553 #5.1.8 Domain of sender address does not exist
- 553 5.3.0 … Address does not exist
- 553 5.3.0 … No such user
- 553 5.3.0 … No such user here
- 553 5.3.0 … User unknown, not local address
- 553-Message filtered. Please see the FAQs section on spamn
- 553 does not have a mailbox here
- 553 RemoteDomain.com does not accept mail sent to recipient@OtherRemoteDomain.com
- 553 sorry, no mail-box here by that name. (#5.1.1)
- 553 sorry, no mailbox here by that name (#5.1.1)
- 553 sorry, rcpt user invalid (#5.7.1)
- 553 sorry, that domain isn’t in my list of allowed rcpthosts
- 553 sorry, that domain isn’t in my list of allowed rcpthosts (#5.7.1)
- 553 sorry, the recipient in not a valid user on this domain (#5.7.1)
- 553 sorry, this recipient doesn’t exist.
- 553 sorry, this recipient is not in my validrcptto list (#5.7.1)
- 553 sorry, your envelope sender is in my badmailfrom list (#5.7.1)
- 553 Your email address is denied.

## Resolving a 553 email error bounceback

The 553 series of errors would typically be a hard bounce, and usually your message is rejected right away. For a better understanding of a soft or hard bounce is, and general email bounceback errors you can read [why does email bounce, bounceback, or error?](/support/email/email-bounce-bounceback-error/)

In our example bounce-back error above the reason the message has failed is because of a misconfigured auto-reply that has failed to first authenticate with the mail server before attempting to relay a reply to a message.