Error Description

SMTP error 504 is a temporary or "5xx" error code returned by a mail server to indicate that the server is not ready to accept a command or request from the sender at the moment. This error signifies a transient issue and is often used to ask the sender to try their request again later.

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What's Causing This Error?

SMTP error 504 can be caused by various factors, including:

• Server congestion: The server may be dealing with a high volume of incoming traffic, causing delays in processing new requests.
• Temporary issues: Network problems, server maintenance, or other short-term issues can result in SMTP error 504.
• Resource constraints: The server might be temporarily low on resources needed to handle incoming requests.

How to fix SMTP Error 504?

• Wait and retry: SMTP error 504 is often a temporary issue. Waiting for a period and then retrying the operation or email delivery is usually the best approach.
• Check server status: Verify if the recipient's server is experiencing issues or undergoing maintenance. Contact the recipient's email administrator for more information.
• Optimize email sending: If you are sending a high volume of emails, consider spreading out the delivery over time to avoid overloading the recipient server.

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SMTP Error 504 Examples

Example 1: "504 5.3.2 Server congested, please try your request again later."

Example 2: "504 5.7.1 Temporary server issue. Your request cannot be processed at the moment."

Example 3: "504 5.4.3 Server maintenance in progress. Please retry in an hour."

Example 4: "504 5.2.0 Resource constraints at the moment. Please try your request later."