The mail system is temporarily not accepting new messages. This could be due to maintenance, system overload, or an administrative decision to pause incoming mail. Retry later.
What Does Error 4.3.2 Mean?
Enhanced status code 4.3.2 means the receiving mail system has temporarily stopped accepting new messages. This is different from a full storage condition (4.3.1) - the server may have plenty of capacity but is intentionally not accepting mail, perhaps for maintenance, upgrades, or load management.
This is a transient condition that should resolve automatically. Your MTA should retry delivery over the next several hours.
Common Causes
- Server undergoing maintenance or upgrades
- System overloaded and temporarily rejecting new mail
- Administrative decision to pause incoming mail
- Anti-spam system temporarily blocking all incoming messages
How to Fix Error 4.3.2
- Wait for automatic retry - this is typically resolved within hours
- If persistent, contact the recipient organization postmaster
Frequently Asked Questions
Bounce code 4.3.2 means the recipient's mail system is temporarily unable to accept incoming messages due to conditions such as an imminent shutdown, excessive load, or scheduled maintenance. This is a temporary error -- the server is operational but has intentionally stopped accepting mail until the condition is resolved. Your sending server will automatically retry delivery.
A 4.3.2 error typically resolves within a few hours once the underlying condition (maintenance, overload, or resource shortage) is addressed. Most email systems automatically retry delivery for 3-5 days, so manual resending is usually unnecessary. If the error persists beyond 24 hours, it may indicate a more serious server problem, and you should contact the recipient's mail administrator or reach the recipient through an alternative channel.
As a sender, wait for the recipient's server to resume normal operations -- your mail system will automatically retry. Do not manually resend immediately, as this creates duplicate messages when the server recovers. If you are the server administrator receiving this error, check that your receive connectors are properly configured, restart the Exchange Transport Service, verify that your mail security appliance IP addresses are whitelisted, and ensure the server has adequate system resources (CPU, memory, disk space).