Sales Loves MarketingBlind carbon copy (BCC) is an email field for sending a copy to someone without the other recipients knowing. Addresses in BCC are hidden from everyone in To and CC, and, when the software handles BCC as intended, from each other.
How does BCC work?
An email has three recipient fields. The internet message standard, RFC 5322, describes them like this:
- To holds the primary recipients.
- CC (carbon copy) holds others who should receive the message, even if it isn't aimed at them. Everyone can see these addresses. See carbon copy.
- BCC holds recipients whose addresses should not be shown to the others.
RFC 5322 lets email software handle BCC in different ways. It can strip the BCC line before sending, send BCC recipients a separate copy, or show an empty BCC line to signal that blind copies exist. That is why some BCC recipients see a hint that they were blind-copied and others don't. The standard also warns that if the separate copy lists every BCC address, each BCC recipient can see the others.
What is the difference between CC and BCC?
| CC | BCC | |
|---|---|---|
| Visible to other recipients | Yes | No |
| Recipient can "reply all" to everyone | Yes | Only to To and CC |
| Typical use | Keep someone openly in the loop | Copy someone discreetly, or hide addresses |
When should you use BCC?
- Introductions. When you introduce two contacts, move the person who made the introduction to BCC so they drop out of the follow-up thread.
- Small group messages to people who don't know each other, such as a meeting reminder to external guests, where sharing everyone's address isn't appropriate.
- Keeping a record. Some CRMs, such as HubSpot, give you a BCC address that saves the email against the contact. Check that your CRM supports this before relying on it.
What are the risks of BCC?
- Human error. Putting a list in CC instead of BCC exposes every address.
- Reply all. RFC 5322 notes that a BCC recipient who replies to all can reveal that they were copied.
- Trust. Secretly copying people into a conversation can damage the relationship if it comes out.
Should you use BCC for marketing emails?
No. For newsletters, customer updates or any message to a list, use an email marketing platform or a mail merge tool. Email platforms also manage consent and unsubscribes. Google's sender guidelines say anyone sending more than 5,000 messages a day to Gmail must support one-click unsubscribe in marketing messages. See email list and GDPR.
Frequently asked questions
What is the difference between CC and BCC?
Everyone can see the addresses in the CC field. Addresses in the BCC field are hidden from the other recipients. Use CC when people should know who else is involved, and BCC when they shouldn't see each other's addresses.
Can BCC recipients see each other?
Not if the email software handles BCC as intended. The email standard, RFC 5322, leaves the details to the software and warns that a copy listing every BCC address would reveal them to each other. Depending on the software, a BCC recipient may or may not see a sign that they were blind-copied.
Should you use BCC for marketing emails?
No. One slip, such as pasting the list into CC, exposes every address. Use an email platform or mail merge instead. A proper email platform also handles unsubscribes, which Google requires from senders of more than 5,000 messages a day to Gmail.