554: Transaction Failed

The 554 SMTP error means the transaction was permanently rejected, often due to spam, a blocklist, or a policy violation. Learn how to investigate.

Published · Last verified · Maintained by TamingDNS

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Permanent Failure (Hard Bounce)
SMTP Code
554
Category
Transaction Failed
Frequency
Common

💬 What This Error Means

The entire conversation was rejected. This is a permanent 'hard bounce' that usually means the server decided your message looked too much like spam, or your server is on a list of untrusted senders.

Common Causes

  • Your email content was flagged as spam by a filter
  • Your sending IP address is on a major blocklist
  • The receiving server has a strict policy that your email didn't meet

How to Fix This

  • Check our Blacklist Checker to see if your IP is being blocked
  • Try simplifying your email. Remove lots of links or large images
  • Verify your SPF and DKIM records to prove you are a legitimate sender

📚 Official Documentation

RFC 5321: SMTP

📋 Real-World Example Messages

These are real bounce message formats you might receive. Paste yours into the Bounce Decoder for instant analysis.

554 Transaction failed
554 5.7.1 Message rejected as spam by Content Filtering

🔧 Related Diagnostic Tools

These tools can help you diagnose and fix this type of bounce:

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SPF Checker
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DKIM Checker
DMARC Builder

🔧 This Bounce Is Related to Email Authentication

Fixing this type of bounce requires correctly configured SPF, DKIM, and DMARC records. Our free Domain Checker analyses all three in one scan and tells you exactly what to fix.

Run a Free Domain Authentication Check →
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Got a bounce message to decode?

Paste your full NDR email, SMTP error line, or mail log fragment to get an instant plain-English diagnosis.

Open the Bounce Decoder →