SMTP Error 452:

What does it mean? And How to resolve this error?

Table of content

Error Description

SMTP error 452 is a transient or "4xx" error code returned by a mail server to indicate that it has encountered temporary resource constraints or exceeded limits, preventing it from accepting or processing an incoming email message at that moment. Unlike permanent errors, SMTP error 452 suggests that the issue is temporary and may be resolved in the future.

What's Causing This Error?

SMTP error 452 can be caused by various reasons, including::

Server overload: The mail server is currently processing a high volume of incoming email traffic, and to prevent further overload, it temporarily rejects new connections or delays email delivery.
Resource constraints: The server may have limited resources (such as CPU, memory, or disk space) available, and it temporarily restricts new email deliveries to manage these resources effectively.
Greylisting: Some mail servers use greylisting as an anti-spam technique. When an unknown sender attempts to send an email, the receiving server initially rejects it with a 452 error. If it's a legitimate sender, the sending server will retry the delivery after a delay, and the email will be accepted.

How to fix SMTP Error 452?

Wait and retry: Since SMTP error 452 is a temporary issue, the best course of action is to wait and retry sending the email later. The receiving server may have been overloaded or temporarily unavailable, and the problem may resolve itself.
Check for greylisting: If you suspect greylisting is causing the error, simply waiting and retrying the email should resolve the issue when the receiving server accepts the email upon the retry.
Investigate resource constraints: If you have control over the receiving server, consider investigating and addressing any resource constraints that may be causing the error.