Question

Debbie’s colleague hasn’t provided her the required details to complete an important report. She is upset by this, and she sends an email to her colleague. She would also like to keep her manager informed about the delay, but without her colleague’s knowledge. What email feature can she use here?

Answer 1

The answer is BCC  

I hope this helps

Answer 2

There are several---guerrillamail, sharklasers and other--- providers that can send anonymous mail. If she named herself in the message, she may be able to let her boss know (where the colleague likely wouldn't dare to look) about the delay.