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Deliverability Letter

552 5.2.2

552 5.2.2 Mailbox Over Quota

Mailbox Full

The recipient’s mailbox is full and cannot accept new mail.

Treat 5.2.2 as a soft bounce. If it repeats over multiple sends, suppress the address to protect deliverability.

Severity

WARNING

Provider

SFR

Last Reviewed

2025-06-01

How to Fix 552 5.2.2

Follow these steps to resolve this SFR SMTP error and restore normal delivery.

  • ✓Retry for a few days before suppressing the contact.
  • ✓Encourage key recipients to free up space or provide alternate addresses.
  • ✓Escalate to sales or support if the mailbox belongs to a major customer.
  • ✓Exclude chronically full mailboxes from high-frequency marketing campaigns.

Helpful Resources

More SFR SMTP Codes

Keep these related troubleshooting guides handy while addressing 552 5.2.2.

421 4.7.0 – 421 4.7.0 Too Many Errors
WARNING
450 4.7.1 – SFR_IN_101 Spam Complaints
ERROR
450 4.7.1 – SFR_IN_102 Virus or Malware Detected
CRITICAL
450 4.7.1 – SFR_IN_103 Too Many SMTP Errors
WARNING

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