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What do bounce error messages 550 5.7.1 and 554 mean and how to resolve them?

Summary

Bounce error messages 550, 5.7.1 and 554 indicate various reasons for email delivery failure, primarily stemming from issues with the recipient's address, sender's reputation, authentication problems, policy violations, or spam-related content. The root causes span from invalid recipient addresses and blocked IPs to content triggers and authentication failures. Resolving these requires verifying recipient addresses, cleaning email lists, improving sender reputation, reviewing email content, ensuring proper authentication (DKIM), contacting ESPs or the recipient's administrator, and investigating potential blocklisting issues.

Key findings

  • Multiple Causes: 550, 5.7.1, and 554 errors arise from a variety of issues, requiring a multi-faceted approach to resolution.
  • Address Issues: Invalid or non-existent recipient email addresses are a common cause.
  • Reputation Problems: Sender's IP or domain being blacklisted or having a poor reputation leads to blocks.
  • Authentication Failures: Improperly configured email authentication methods like DKIM can cause delivery failures.
  • Policy and Spam: Email content violating recipient policies or triggering spam filters results in rejection.

Key considerations

  • Address Verification: Always verify the recipient's email address to ensure it's correct and active.
  • List Hygiene: Regularly clean your email list by removing hard bounces and invalid addresses.
  • Reputation Management: Monitor your sender reputation and take steps to improve it to avoid blacklisting.
  • Authentication Setup: Ensure proper configuration of email authentication methods (DKIM, SPF, DMARC).
  • Content Review: Review email content to avoid spam triggers and comply with recipient policies.
  • ESP/Admin Contact: Contact your ESP or the recipient's email administrator for investigation and resolution assistance.

What email marketers say

9 marketer opinions

Bounce error messages 550 and 554 indicate that an email has not been delivered to the recipient. These errors are generally considered permanent failures, meaning the receiving server could not or would not accept the message. Common reasons include invalid recipient addresses, policy blocks, spam filtering, sender blacklisting, content filtering, or security policy violations. Resolutions involve verifying the recipient's email address, cleaning your email list, improving sender reputation, reviewing email content, contacting the recipient to whitelist the sender, or contacting the postmaster.

Key opinions

  • 550/554 Errors: These indicate permanent email delivery failures.
  • Invalid Addresses: Often caused by incorrect or non-existent recipient email addresses.
  • Policy/Spam Blocks: Recipient servers may block emails due to spam filtering, blacklisting, or policy violations.
  • Content Issues: Email content may trigger spam filters, leading to rejection.
  • List Hygiene: Maintaining a clean email list by removing bounced addresses is crucial.

Key considerations

  • Verify Addresses: Always double-check recipient email addresses for accuracy.
  • Sender Reputation: Monitor and improve your sender reputation to avoid blacklisting.
  • Content Review: Review email content for potential spam triggers and ensure compliance with policies.
  • List Management: Regularly clean your email list by removing hard bounces to improve deliverability.
  • Contact Recipient/Postmaster: If issues persist, contact the recipient or postmaster for assistance.

Marketer view

Email marketer from EmailToolTester says 550 and 554 error codes mean the email was blocked by the recipient's server. Check to make sure you're not sending spam-like content and that the recipient's address is correct.

25 Jan 2025 - EmailToolTester

Marketer view

Email marketer from SparkPost says 550 errors mean that the message wasn't delivered because the destination mailbox was invalid or the user doesn't have permission to receive messages. They advise handling these failures and removing the email addresses to improve deliverability.

10 May 2022 - SparkPost

What the experts say

4 expert opinions

Bounce error messages, including 550 errors, often indicate issues related to spam/reputation blocking, problems with the sending IP address (especially if using a shared IP like Amazon's), or failures in email authentication (like DKIM). The primary resolutions involve contacting your Email Service Provider (ESP) or Amazon if on a shared IP, ensuring proper email authentication setup, and investigating your sending infrastructure for blocklisting or other deliverability issues.

Key opinions

  • Reputation Blocking: Bounce messages suggest the receiving ISP is blocking emails due to sender's reputation.
  • Shared IP Issues: Using shared IPs, like those from Amazon, can lead to deliverability problems if the IP is flagged.
  • Authentication Failures: Problems with email authentication, such as DKIM, can cause emails to bounce.
  • Infrastructure Problems: Sending infrastructure may have issues with blocklisting or overall configuration.

Key considerations

  • Contact ESP/Amazon: Reach out to your ESP or Amazon (if using their IPs) to investigate and resolve IP reputation issues.
  • Verify Authentication: Ensure DKIM and other email authentication methods are correctly configured.
  • Check Sending Infrastructure: Examine your sending infrastructure for potential blocklisting or configuration errors.
  • Monitor Reputation: Regularly monitor your sender reputation to identify and address deliverability problems proactively.

Expert view

Expert from Email Geeks explains the bounce messages indicate spam/reputation blocking, and the receiving ISP likely doesn't want the mail. Because Megan is not the ESP, she should contact her ESP to get more information.

6 Jul 2024 - Email Geeks

Expert view

Expert from Email Geeks suggests that since Megan is on a shared Amazon IP, the issue is likely with Amazon's IP reputation and recommends that Megan contact Amazon.

28 Oct 2021 - Email Geeks

What the documentation says

5 technical articles

The 550 5.7.1 and 554 bounce error messages generally indicate email delivery issues stemming from various causes. 550 errors can signify problems with the recipient's email address (non-existent or unavailable) or delivery policy violations, potentially due to sender authorization issues or policy non-compliance. 554 errors suggest rejection due to security policies, possibly related to local blocklists or content-based blocks. Resolving these issues often involves contacting the recipient's email administrator or the sender's email service provider for investigation, verifying email addresses, and reviewing relevant documentation to understand specific filtering rules.

Key findings

  • 550 Error: Indicates issues with recipient address or delivery policy violation.
  • 554 Error: Indicates email rejection due to security policies.
  • Recipient Issues: The recipient email address might be unavailable or non-existent.
  • Policy Violations: Sender might lack authorization or violate recipient system policies.
  • Security Blocks: Email might be rejected due to local blocklists or content filters.

Key considerations

  • Contact Admins/ESPs: Contact recipient's email administrator or sender's ESP for investigation.
  • Verify Addresses: Double-check recipient email addresses for accuracy.
  • Review Documentation: Consult relevant documentation (e.g., Mimecast's) to understand specific filtering rules.
  • Authorization Checks: Ensure the sender has the necessary authorization to send emails.
  • Policy Compliance: Verify that the email content complies with recipient system policies.

Technical article

Documentation from Microsoft Learn explains that the 550 5.7.1 error indicates a general delivery issue, often due to sender IP address being blocked or a problem with the sender's email authentication. Resolution involves contacting the recipient's email administrator or the sender's email service provider to investigate and resolve the blocking or authentication issue.

13 Apr 2024 - Microsoft Learn

Technical article

Documentation from Google Workspace Admin Help indicates that a 550 error can mean that there is a problem with the recipient's email address. Google suggests you contact them by phone to confirm the address and check if they are rejecting your emails, or contact the domain host to confirm if the domain is accepting emails.

10 Dec 2021 - Google Workspace Admin Help

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