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Email error 452 4.2.2: Insufficient storage or too many recipients

The server cannot accept the message at the moment, usually because the mailbox is full or the message has too many recipients for one session.

Temporary failure (soft bounce)

What it means

The server cannot accept the message at the moment, usually because the mailbox is full or the message has too many recipients for one session.

Common causes

  • The recipient mailbox is over its quota.
  • The server has no free disk space.
  • You addressed too many recipients in one message or connection.
  • A temporary resource limit on the receiving side.

How to fix it

  1. Retry later.
  2. Send in smaller batches and avoid long recipient lists in a single message.
  3. If one address fails again and again, pause sending to it.
  4. Use one message per recipient for marketing mail.

How to prevent it

Most bounces come from addresses that were never checked. Verify each address before you send: syntax, domain, mailbox and risk are checked without sending a message. Test a single address with the free email checker or upload a whole list for bulk verification.

Verify an email address free · Clean a whole list · MX lookup · SPF, DKIM and DMARC checker

Frequently asked questions

Is this a hard bounce?

No. It is temporary unless it keeps happening for the same address.

What counts as too many recipients?

It depends on the server. Small batches are safer.

Other error codes

550 5.1.1User unknown (mailbox does not exist) 550 5.7.1Message rejected by policy (blocked) 550 5.7.26Sender not authenticated (SPF/DKIM/DMARC) 550 5.4.1Recipient address rejected: access denied 552 5.2.2Mailbox full (over quota) 553 5.1.3Invalid address syntax

All email error codes