How do I email a group without showing everyone's address?

This is a two-second habit that prevents one of the most common accidental data breaches in the country. Schools, clubs, charities and small businesses do it wrong constantly.

Step by step

1. Understand the three fields.To is the intended recipient. CC is a visible copy. BCC is a blind copy — those recipients receive the message but nobody can see their addresses, including each other.
2. Find BCC if it is hidden.Some mail programs hide it behind a small BCC link near the To field, or in an options menu. Once used it usually stays visible.
3. Put yourself in To.A message with an empty To field is more likely to be filtered as junk. Addressing it to yourself and BCC-ing everyone else avoids that.
4. Check before sending.Look at where the addresses actually are. Autocomplete drops them into To by default, and moving them afterwards is easy to forget.
5. Understand why it matters legally.An email address is personal data. Disclosing a list of them without consent is a breach under UK data protection law, and it is more serious when the list itself reveals something — a support group, a clinic, a legal matter.
6. Use a group or distribution list for regular sending.A saved group means one entry rather than fifty pasted addresses, which removes the chance of error. Put the group in BCC as normal.
7. Use a mailing service for anything large or regular.Above roughly fifty recipients, a proper mailing service handles unsubscribes, avoids sending limits and is far less likely to be filtered.
8. Tell recipients they cannot see each other.A line saying 'sent by BCC so addresses stay private' prevents people replying to all and prevents confusion about who received it.

Tips

• Reply-all to a BCC message only reaches the sender, which is usually what you want. Recipients cannot accidentally reach the whole list.
• If people need to reply to each other — a committee, a family group — use a shared group chat or a mailing list rather than BCC, which is deliberately one-directional.
• Personal mailboxes have hourly and daily sending limits. Very large BCC lists can trigger a temporary block on the account.

Common mistakes

• Putting the list in CC to save time — Every recipient sees every address, they can be harvested and forwarded, and it is the classic accidental disclosure. It cannot be undone.
• Assuming BCC hides everything — It hides addresses from each other, not from you or from the mail provider. It is privacy between recipients, not anonymity.

If it doesn't work

Questions people ask