Docs Error Library Configuration Errors Error 501-5.5.2: Cannot Decode Response

Error 501-5.5.2: Cannot Decode Response

What Is Causing This Error?

The “Error 501-5.5.2: Cannot Decode Response” often results from incorrect SMTP configuration or authentication failures. Specifically, it can happen if the SMTP server’s response isn’t understood by the client, possibly due to a misconfigured server address, port, or use of SSL/TLS settings that aren’t supported by the server.

It’s also seen in scenarios involving SMTP OAuth 2.0, where the authentication process doesn’t proceed as expected.

Resolving the Error – Solution

To fix ‘Error 501-5.5.2’, ensure your SMTP settings are accurate, including the server address, port, and whether SSL/TLS is required. For WordPress users, configuring your site’s email functionality with the Easy WP SMTP plugin can streamline this process. This plugin allows for easy setup of SMTP settings, ensuring that emails are sent through a reliable SMTP server with the correct authentication methods, potentially circumventing issues like this error.

It’s also advisable to review and test your OAuth 2.0 configurations if applicable, ensuring that tokens are valid and correctly implemented.

That’s it! Now you know how to troubleshoot and fix Error 501-5.5.2.

If you’d like to learn about other common errors, check out the following tutorials: