550 5.2.0: Other Mailbox Status

The 550 5.2.0 error is a generic mailbox-level rejection. Learn what this SMTP bounce means, what causes it, and how to resolve it.

Published · Last verified · Maintained by TamingDNS

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Permanent Failure (Hard Bounce)
SMTP Code
550
Enhanced Code
5.2.0
Category
Other Mailbox Status
Frequency
Common

🔢 Enhanced Status Code Breakdown: 5.2.0

Component Value Meaning
Class 5 Permanent failure (Hard bounce)
Subject 2 Mailbox status
Detail 0 Other Mailbox Status

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

💬 What This Error Means

Something is wrong with the recipient's mailbox, but the server didn't give a specific reason. This is a generic 'mailbox error' that can mean anything from a temporary glitch to a settings problem on their end.

Common Causes

  • A temporary problem with the recipient's mail server
  • The person's inbox has a specific rule that blocked your message
  • The mailbox is in the middle of a migration or update

How to Fix This

  • Try sending your message again in a few hours
  • If it keeps happening, you might need to reach out to the person through another channel

📚 Official Documentation

RFC 3463: Enhanced Status Codes

📋 Real-World Example Messages

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

550 5.2.0 Other or undefined mailbox status
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