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Bounce Decoder: 550 5.2.0

SPF, DKIM, DMARC, FCrDNS, Blacklists & Inbox Prediction

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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 and how to resolve it.

🔴
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
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

The mailbox exists but cannot receive your message for an unspecified reason. This is a catch-all mailbox status code when no more specific code applies.

Common Causes

  • Mailbox-level policy rejection
  • Server configuration preventing delivery to this mailbox
  • Account in a transitional state (migration, suspension)

How to Fix This

  • Contact the recipient through another channel to confirm their address is active
  • Wait and retry — the condition may be temporary despite the 5xx code

📋 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

🔗 Related Error Codes

550 5.2.1
Mailbox Disabled
552 5.2.2
Mailbox Over Quota

📚 Official Documentation

↗ RFC 3463 — Enhanced Status Codes
🔍

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