550 5.7.367 Remote Server Returned Not Permitted to Relay

Nene Aly

By Nene Aly / Updated on March 4, 2024

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The error message '550 5.7.367 Remote Server Returned Not Permitted to Relay' is a common issue faced by many email users. This error occurs when the email server rejects an outgoing message due to unauthorized relay attempts. In this essay, we will explore the problem in detail, discuss its potential causes, and provide effective solutions to resolve it.

Understanding the Problem

The error message '550 5.7.367 Remote Server Returned Not Permitted to Relay' usually appears when trying to send an email through an email server that does not allow relaying. Email relaying refers to the process of sending an email through a server that is not the intended recipient's server. This practice is often restricted to prevent spam and unauthorized use of email servers.

The error message signifies that the email server encountered an attempt to relay an email that was not permitted, resulting in the rejection of the outgoing message.

Potential Causes

There are several potential causes for the '550 5.7.367 Remote Server Returned Not Permitted to Relay' error:

  1. Incorrect SMTP server settings: The error can occur if the SMTP server settings are not properly configured. This includes incorrect server addresses or authentication credentials.
  2. Blocked IP address: The email server may have blocked the IP address from which the email is being sent. This could be due to suspicious activity or previous identification as a source of spam.
  3. Disabled relay permissions: The email server's configuration may limit relay permissions, either for specific users or for the entire server. If the sending email account does not have the necessary permissions, the relay attempt will be rejected.


Solution 1: Verify SMTP Server Settings

  1. Check the SMTP server address and ensure it is correct.
  2. Verify the port number being used for SMTP communication.
  3. Ensure that the authentication credentials, such as username and password, are correct and properly entered in the email client settings.
  4. Try using different authentication methods, such as SSL or TLS, and see if the issue persists.
  5. Restart the email client and attempt to send the email again.

Solution 2: Unblock IP Address

  1. Contact the email server administrator and request the unblocking of the IP address.
  2. Provide any necessary information to prove that the IP address is not involved in suspicious activities.
  3. Once the IP address is unblocked, attempt to send the email again.
  4. If the issue persists, consider using a different IP address or contacting your internet service provider for assistance.
  5. Regularly monitor the IP address for any suspicious activities to prevent future blocking.

Solution 3: Check Relay Permissions

  1. Review the email server's configuration and ensure that relay permissions are enabled.
  2. If only specific users are affected, check their account settings and ensure they have the necessary relay permissions.
  3. If relay permissions are disabled for the entire server, consider contacting the server administrator to request enabling them for the affected account.
  4. Try using a different email account with proper relay permissions to send the email.
  5. If none of the above solutions work, consider using a different email server or consulting with a professional IT support team for further assistance.

Software Recommendation

One recommended software to help diagnose and resolve email relay errors is 'SMTP Diagnostics'. This tool offers a comprehensive analysis of SMTP server settings, identifies any misconfigurations, and provides step-by-step instructions to fix them. It also allows users to test email sending directly from the software interface, making troubleshooting more efficient.

However, keep in mind that 'SMTP Diagnostics' is a paid software, and users should evaluate their specific needs and budget before making a purchase.

FAQ - Frequently Asked Questions

Q: What is an SMTP server?

A: SMTP (Simple Mail Transfer Protocol) is a standard protocol used for sending emails across networks. An SMTP server is responsible for routing and delivering outgoing emails to the intended recipients.

Q: Why is email relaying restricted?

A: Email relaying is restricted to prevent spamming and unauthorized use of email servers. By limiting the ability to relay emails, servers can maintain better control over the email traffic and reduce the risk of abuse.

Q: Can I use a different email server to avoid the relay error?

A: Yes, if the current email server consistently returns '550 5.7.367 Remote Server Returned Not Permitted to Relay' errors, it might be worth considering a different email server or service that allows for proper relay permissions.

Q: How can I contact the email server administrator?

A: Contact information for the email server administrator is typically available through the email service provider or organization with which you are associated. Check their support documentation or website for relevant contact details.

Q: What should I do if the SMTP Diagnostics tool doesn't resolve the issue?

A: If 'SMTP Diagnostics' does not resolve the issue, consider seeking assistance from a professional IT support team or contacting your email service provider directly. They may have additional troubleshooting steps or specific recommendations based on their infrastructure.

Q: Can I prevent my IP address from being blocked again?

A: Yes, you can minimize the chances of your IP address being blocked by following good email practices. This includes using secure email clients with proper authentication methods, avoiding sending large volumes of unsolicited emails, and promptly responding to any abuse reports or warnings from your email service provider.

Q: Are there any free alternatives to SMTP Diagnostics?

A: Yes, there are free alternatives to SMTP Diagnostics, such as 'SMTPTester' and 'MX Toolbox', which offer similar features for diagnosing and troubleshooting SMTP server issues. However, the functionality and user interface may vary, so it's recommended to explore multiple options before choosing the most suitable one for your needs.


1. SMTP: Simple Mail Transfer Protocol - A standard protocol used for the transmission of emails between servers.

2. IP Address: Internet Protocol Address - A unique numerical label assigned to each device connected to a computer network.

3. Relay: In the context of email, it refers to the process of sending an email through a server that is not the intended recipient's server. This process is often restricted to prevent spam and unauthorized use of email servers.

Tips for Preventing '550 5.7.367 Remote Server Returned Not Permitted to Relay' Errors

  1. Regularly check and update your email client settings, especially the SMTP server details.
  2. Ensure that your IP address is not involved in any suspicious activities to avoid being blocked by email servers.
  3. Be cautious while sending emails in bulk, especially unsolicited ones, as they may trigger spam filters and lead to relay errors.


The '550 5.7.367 Remote Server Returned Not Permitted to Relay' error can be frustrating for email users, but with a better understanding of the problem and the provided solutions, it can be successfully resolved. By verifying SMTP server settings, addressing IP blocking, and checking relay permissions, users can overcome this error and ensure smooth email communication. Additionally, utilizing software like 'SMTP Diagnostics' can simplify the troubleshooting process. Remember to follow best practices for email usage and stay vigilant to prevent future relay errors.

Nene Aly
Nene Aly · Editor