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Bounce Decoder: 554 5.4.6

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554 5.4.6 — Routing Loop Detected

The 554 5.4.6 bounce means your email got caught in a routing loop between mail servers. Learn what causes mail loops and how to fix them.

🔴
Permanent Failure (Hard Bounce)
SMTP Code
554
Enhanced Code
5.4.6
Category
Routing Loop Detected
Frequency
Common

🔢 Enhanced Status Code Breakdown: 5.4.6

Component Value Meaning
Class 5 Permanent failure
Subject 4 Network and routing
Detail 6 Routing Loop Detected

Per RFC 3463 Enhanced Mail System Status Codes. Class (X) = severity, Subject (Y) = category, Detail (Z) = specific condition.

💬 What This Error Means

The email was caught in a routing loop — bouncing between servers without reaching its destination. This is a mail server configuration problem.

Common Causes

  • Circular mail routing or transport rules
  • Misconfigured forwarding creating a loop
  • Conflicting relay settings between servers

How to Fix This

  • Review mail routing rules and forwarding settings on your server
  • Check for circular forwarding chains
  • Contact your email administrator to audit mail flow rules

📋 Real-World Example Messages

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

554 5.4.6 Too many hops
554 5.4.6 Hop count exceeded - possible mail loop

🔗 Related Error Codes

550 5.4.4
No Route to Destination
550 5.4.7
Delivery Time Expired

📚 Official Documentation

↗ RFC 5321 — Mail forwarding and loops
🔍

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