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Fixing the 550 5.7.1 [SB02] error

If you're receiving this error, it means we have detected abuse originating from your domain. The domain may be:

  • Sending spam
  • Sending high volumes of suspicious bulk email
  • Generating complaints
  • Attempting to send to a large numbers of invalid recipients

How can I unblock my account as an end user?

Secure your account against compromise by performing the following:

  • Change your password. Ensure your new password has a minimum length of eight characters and uses a mixture of upper and lower case letters, numbers, and special characters.
  • Verify that your operating system is running with the latest security updates.
  • Update your anti-virus software and conduct a full scan of your system to ensure that a spammer has not installed spam-sending malware on your computer.

If these steps do not resolve the problem, please file a support request with your web hosting provider.  

How can I unblock an end user account as a service provider?

1. Enable "Receive Notifications" by logging into the MailChannels Console, if you have not done so already. Refer the following article on enabling notifications.

2. Every time an email is blocked with "550 5.7.1 [SB02] Your email address has been blocked due to complaints.", a notification gets sent out to the email address you have configured. The notification will also contain a link to unblock the account. If you automate the process, you can POST to the URL to unblock the account.

IMPORTANT: If an account is unblocked without securing the account, it would get blocked again. An account can be unblocked without any manual intervention only once every 30 days. 

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    John O'Connor

    Your servers are blocking my email providers (BTConnect). I must be one of millions of BT customers, I dont understand why you need to block a major providers emails

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