Monthly Archives: June 2020

Microsoft O365 Bulk Complaint Level

When targeting Office365 hosted mailboxes, Microsoft assigns a Bulk Complaint Level to incoming messages originating from bulk mailers.The BCL rating is being assigned the same way the Spam Confidence Level (SCL) through an appended X-header. A high BCL level indicates the related message is likely to be spam.To determine the BCL level, Microsoft uses both… Read More »