Content Filtering is currently configured to reject messages that have a Spam Confidence Level (SCL) value of {4}. This is ...

Content Filtering is currently configured to reject messages that have a Spam Confidence Level (SCL) value of {4}. This is the default value for the SCL threshold. However, the recommended value is 7. You can configure SCL thresholds on the Anti-spam tab in the Exchange Management Console or by using the Set-ContentFilterConfig cmdlet in the Exchange Management Shell.