Is it ever appropriate to use the bcc email function for internal office emails? — Mike in Flower Mound, TexasAunt Dandelion answers:
Mike, use of the blind copy (bcc) function can be very important. When general information or a request for help is sent to a large list of employees, many people use “reply all” to shoot back a comment or provide a resource. This results in mass emails that clog inboxes and provide an unwelcome distraction for the bulk of the recipients. In cases like this, the general list should be placed in the bcc: field to obviate the problem. The sender can start their email with a line such as “Message to all employees,” or “Request for research by the Strategy Team” so the recipients know why they received it.
Other than this scenario, using the bcc: field would mean you are trying to inform someone of an ongoing issue without the other recipients knowing that person has been copied. This is sneaky and borders on dishonesty. Take your problem to the proper authority in private.