We all have that one petty coworker who swears by the BCC line because it helps her spread office gossip. Maybe that person is you. Either way, most people who regularly use the BCC line have ill intentions. But, the BCC line can, and should, be used to be productive, not devious.

Here’s when you should use the BCC line:

When you want to include people on a thread who may not want their email addresses disclosed. Maybe you’re emailing a large group of people about a work event or you’re emailing your entire client list about a new product. So, to protect everyone’s privacy, you should put their email addresses in the BCC line. This way, no email addresses are visible and you avoid having to send a bunch of separate emails.

Here’s when you should not use the BCC line:

If you’re using the BCC line to disclose something you shouldn’t or spread drama then you’re entering dangerous territory. The contents of the BCC line can be easily uncovered if the right tech savvy person cares to look. So, don’t embarrass yourself or lose your job because you felt petty one afternoon and recklessly used the BCC line. Also, remember that the recipient of your email may not realize she is in the BCC line and might hit “reply all.” Don’t risk it.