How to Fix Remote server returned 550 5.7.520 Access denied

Learn effective solutions to resolve the "Remote server returned 550 5.7.520 Access denied" error on our website. Expert tips and step-by-step guides available.

Microsoft 365 is a popular cloud-based productivity suite used by millions of individuals and businesses worldwide. With its various features and tools, it has become an essential part of many organizations' daily operations. However, like any other technology, it is not immune to errors and issues. One such error that users may encounter is the 'Remote server returned 550 5.7.520 Access denied' message. This error mainly occurs when trying to forward emails to recipients outside the organization. In this article, we will discuss how to fix this error in Microsoft 365.

What is the Remote server returned 550 5.7.520 Access denied error?

Before we dive into the solution, let us first understand what this error means. When a user tries to forward an email to an external recipient, the Microsoft 365 server checks for any potential spam or security threats. If the server detects any suspicious activity, it may block the email from being forwarded and return the error message 'Remote server returned 550 5.7.520 Access denied.'

This is a security measure put in place by Microsoft to protect users from potential threats. However, it can also cause inconvenience for users who need to forward emails to external recipients regularly.

How to fix the Remote server returned 550 5.7.520 Access denied error?

To resolve this error, you need to navigate to the Office365 Security Center and make some changes in the Anti-spam settings.

1. Navigate to the Office365 Security Center: To access the Office365 Security Center, you need to have admin rights. Log in to your Microsoft 365 account and click on the Admin app. Under the Admin app, click on the Security option to open the Security & Compliance Center. Then, navigate to Threat management > Policies and Rules or Policy > Anti-spam.

2. Allow External Forwarding for individual users: If you need to allow specific users to forward emails to external recipients, you can create a new policy. Under the Anti-spam section, click on the '+' icon to create a new policy. Enter the name and description for the policy and select the users for whom you want to allow external forwarding. Then, under the Protection Settings options, change the Automatic forwarding rules setting to 'On – Forwarding is enabled.' Review the rule and click on Create to save the changes.

3. Allow External Forwarding for all users: If you want to allow all users in your organization to forward emails to external recipients, you can do so by opening the Anti-spam outbound policy. Under the Anti-spam section, click on the policy, and then click on Edit policy. In the Protection Settings options, change the Automatic forwarding rules setting to 'On – Forwarding is enabled' and click on Save to apply the changes.

4. Test the changes: Once you have made the necessary changes, try forwarding the email that was previously blocked. If the error does not occur, it means that the issue has been resolved. However, if the error persists, you may need to check for any other settings or policies that may be blocking the email.

The 'Remote server returned 550 5.7.520 Access denied' error in Microsoft 365 can be frustrating for users who need to forward emails to external recipients frequently. However, with the above steps, you can easily fix this error and continue your work without any interruptions. It is essential to note that the Anti-spam settings are crucial in protecting your organization from potential threats, so make sure to review them regularly and make changes as needed.