Reminder: BCC hides your contacts
I’m writing this today as a public service. You may notice that your mail client typically contains 3 address entries: To, CC, and BCC.
To is self explanatory, but the other two are often misused. CC, or carbon copy, sends the same message to whatever addresses are in that field. What people often forget is that everyone who receives the email can view all the addresses associated with the message. To solve that problem, every email client uses BCC or blind carbon copy. This sends the same message to all the addresses, but hides them so that it appears that they are the only one receiving the email. This is great for sending a message to your entire address book without everyone knowing who you have contact information for. Sadly, spammers have also capitalized on this feature, as many now send messages in this way.
Next time you send emails to multiple people, remember the benefits of using BCC. Otherwise, people may know you’re friends with email@example.com.