What is the “CC” field?

Still have a question, spotted an error, or have a better explanation or a source we should cite?

The CC field (short for "Carbon Copy") is where you list additional recipients who should see an email but aren't the primary audience. Everyone in To and everyone in CC can see each other's addresses. It's the email equivalent of saying "FYI" to a group.

But Here's what happens behind the scenes: when you send an email, the mail server treats To and CC recipients identically. Each address gets its own RCPT TO command during SMTP delivery. Technically, there's no difference between To and CC from a delivery standpoint. The distinction is purely social.

The social signal matters. Putting someone in To says "this is for you, action expected." Putting someone in CC says "keep you in the loop, no response needed." That's why you CC your boss on a client email (they're informed but not the main recipient) or CC a team member who needs context but isn't directly involved.

Where CC becomes a deliverability issue: large CC lists. If you're sending the same message to 50 people and listing them all in CC, Gmail and Outlook may flag it as bulk mail or spam. Mailbox providers see long recipient lists as a spam signal. If you're sending to more than 5-10 people at once, use BCC instead (recipients can't see each other) or switch to an ESP like Mailchimp or Brevo for proper bulk sending.

One common mistake: using CC for newsletters or marketing campaigns. Don't. Marketing emails belong in a proper ESP where recipients are hidden from each other and unsubscribe management is built in. CC is for internal team communication, small group coordination, or keeping stakeholders informed on one-to-one threads.

And if you're deciding between To, CC, or BCC, ask yourself: Does everyone need to see who else is on this email? If yes, CC is fine. If no, use BCC. If you're sending the same message to more than a handful of people, you probably shouldn't be using either.

Contributors

Who worked on this answer

Every name links to their profile. Every company links to their site. Real people, real accountability.

Yanna-Torry (YT) Aspraki

Founder · Author

Review My Emails

Ask an AI · tailored to your setup

Tell Claude about your CC situation →

I read this on the Email Almanac about CC (Carbon Copy): "CC lists additional recipients who can see each other's addresses. It's technically identical to To from a delivery perspective, but signals 'FYI' socially. Large CC lists can trigger spam filters. CC is for small group coordination and keeping stakeholders in the loop, not for newsletters or bulk sending." Help me figure out how this applies to MY situation: 1. Should I be using CC, BCC, or an ESP for my use case? 2. If I'm using CC for team emails, at what list size should I switch to BCC or a proper sending tool? 3. Could my current CC usage be causing deliverability issues? 4. What's the right setup for keeping people informed without hitting spam filters? --- My details (the more you share, the better the advice): - Current use case: [team updates, client communication, stakeholder FYIs, internal coordination] - Typical recipient count: how many people are you CC'ing per email? - Email client: Gmail, Outlook, Apple Mail, etc. - Frequency: how often are you sending these CC'd emails? - Any delivery issues: emails landing in spam, complaints, bounces?

Edit the yellow boxes, then send to the AI of your choice.