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Benefits of BCC
This tip brought to you by the Department of Homeland Security & US-CERT
Although in many situations it may be appropriate to list email recipients in the To: or CC: fields, sometimes using the BCC: field may be the most desirable option.
What is BCC?
BCC, which stands for blind carbon copy, allows you to hide recipients in email messages. Unlike addresses in the To: field or the CC: (carbon copy) field, addresses in the BCC: field cannot be seen by other users.
Why would you want to use BCC?
There are a few main reasons for using BCC:
- Privacy — Sometimes it's beneficial,
even necessary, for you to let recipients know who else is receiving
your email message. However, there may be instances when you want to
send the same message to multiple recipients without letting them know
who else is receiving the message. If you are sending email on behalf of
a business or organization, it may be especially important to keep lists
of clients, members, or associates confidential. You may also want to
avoid listing an internal email address on a message being sent to
external recipients.
Another point to remember is that if you use the To: or CC: fields to list all of your recipients, these same recipients will also receive any replies to your message unless the sender removes them. If there is potential for a response that is not appropriate for all recipients, consider using BCC. - Tracking — Maybe you want to access or archive the email message you are sending at another email account. Or maybe you want to make someone, such as a supervisor or team member, aware of the email without actually involving them in the exchange. BCC allows you to accomplish these goals without advertising that you are doing it.
- Respect for your recipients — Forwarded
email messages frequently contain long lists of email addresses that
were CC'd by previous senders. These addresses are highly likely to be
active and valid, so they are highly valuable to spammers. Furthermore,
many email-borne viruses harvest email addresses contained in messages
you've already received (not just the To: and
From: fields, but from the body, too), so those long
lists in forwarded messages pose a risk to all the accounts they point
to if you get infected.
Many people frequently forward messages to their entire address books using CC. Encourage people who forward messages to you to use BCC so that your email address is less likely to appear in other people's inboxes and be susceptible to being harvested. To avoid becoming part of the problem, in addition to using BCC if you forward messages, take time to remove all existing email addresses within the message. The additional benefit is that the people you're sending the message to will appreciate not having to scroll through large sections of irrelevant information to get to the actual message.
How do you BCC an email message?
Most email clients have the option to BCC listed a few lines below the To: field. However, sometimes it is a separate option that is not listed by default. If you cannot locate it, check the help menu or the software's documentation.
If you want to BCC all recipients and your email client will not send a message without something in the To: field, consider using your own email address in that field. In addition to hiding the identity of other recipients, this option will enable you to confirm that the message was sent successfully.
Authors: Mindi McDowell, Allen Householder
Produced 2004 by US-CERT, a government organization. You are permitted to reproduce and distribute the US-CERT Tips in whole or in part, without changing the text you use, provided that you include the copyright statement or "produced by" statement and use the document for noncommercial or internal purposes. For commercial use or translations, send your email request to webmaster@us-cert.gov.
