If you or a user is getting this 5.7.1 error, it means the sender has been blocked because it has been sending a high volume of spam through our system.
An individual message might be blocked if it contains suspicious-looking text or if the sender has a history of sending unsolicited messages. However, in order to trigger the [CSR] rejection, a sender must have sent a considerable volume of spam in a short period of time.
If a sender is blocked with [CSR], chances are the sender's user account or server environment has been compromised by a spammer. Here are some steps that can be taken to secure a sender environment depending on the type of user:
|End User||End users include all types of email users including webmail users and those sending email from mobile devices and desktop software such as Outlook® or Thunderbird.||Change your password and do a full virus scan to remove any trojan horse software.|
|Server Administrator||Server administrators include people administering dedicated and shared servers that submit email to MailChannels for final delivery.||Scan for root kits and ensure all security patches, operating system updates, and application updates have been installed.|
|Application Administrator||Application administrators include people administering web forums such as Joomla!®, shopping cart software, and other e-commerce applications (generally any server-based application that might have access to send email).||Ensure applications such as Joomla! are updated to the latest release and that no outstanding security vulnerabilities have been left unpatched.|
Our system will automatically remove this block once spamming stops. No manual intervention is required to unblock the account, and filing a support ticket with us will not speed up the process.
If you're still encountering errors or getting false positives, please ask us for help.