Temporary FailureMedium Severity

SMTP Error 452 4.2.2

Mailbox Full / Over Quota

The recipient's mailbox has exceeded its storage quota.

What This Error Means

The recipient's email account has run out of storage space and cannot accept new messages. This is typically a temporary condition that resolves when the user clears their mailbox.

Common Causes

  • 1Recipient hasn't checked email in a long time
  • 2Large attachments filling up the mailbox
  • 3Account has a small storage quota
  • 4Recipient is receiving too much email

How to Fix It

  • 1Retry delivery after 24-48 hours
  • 2Contact recipient through alternative channels
  • 3After multiple failures, consider removing from active list
  • 4Mark as soft bounce and retry with decreasing frequency

Prevention with Whylidate

Prevent this error before it happens by validating email addresses with Whylidate. Our real-time verification catches invalid addresses, full mailboxes, and policy issues before you send.

Quick Reference

Error Code
452 4.2.2
Category
Temporary Failure
Severity
Medium
Should Retry?
Yes, with backoff
View All SMTP Errors