How to Use BCC in Outlook (and What Happens When You Do)

To use BCC in Outlook, open a new message, select Options > Show fields > Show Bcc in new Outlook (or Options > Bcc in classic Outlook), and type the hidden recipients on the Bcc line.

Everyone on that line gets a copy, and nobody else who receives the message can see their names. This guide covers each Outlook version, what every recipient sees, the reply-all trap, and the recipient limits Microsoft documents.

How to Send an Email Using BCC in Outlook

These steps are for new Outlook for Windows, the version Microsoft's Bcc help page documents first. Classic Outlook differs only in step 2.

1. Select New mail, or open a reply to an existing message.
2. Select Options > Show fields > Show Bcc. In classic Outlook, select the Options tab and then Bcc in the Show Fields group.
3. Type the visible recipients in To and, if needed, Cc.
4. Type each hidden recipient on the Bcc line. Outlook suggests matching contacts as you type, the same as in To.
5. Write the subject and message, attach any files, then select Send.

To hide the line again, repeat step 2; the same command switches it off.

What BCC Means in Outlook

BCC stands for blind carbon copy. Microsoft defines it simply: a person on the Bcc line receives a copy of the email without their name being visible to the other recipients.

Outlook has three address lines, and the only difference between them is who can see whom.

Line	Who receives the email	Who can see this line's names	Typical use
To	Yes	Every recipient	People who must read or act on the message
Cc	Yes	Every recipient	People kept informed in the open
Bcc	Yes	Only you, the sender	People who should get a copy without being listed

How to Show the BCC Field in Outlook

The Bcc line is hidden by default in most Outlook versions. Find your version below. If you are not sure which Windows version you have, the new Outlook steps fail on classic Outlook, so try the other row.

Your Outlook	How to show Bcc	Source status
New Outlook for Windows	Open a new message or reply, then select Options > Show fields > Show Bcc	Documented by Microsoft
Classic Outlook for Windows (Microsoft 365, 2024, 2021, 2019, 2016)	In an open message, select the Options tab, then Bcc in the Show Fields group (older builds label it Show Bcc under Message Options > Fields)	Documented by Microsoft
Outlook on the web and Outlook.com	Microsoft's Bcc help page does not list a separate web path. Start with the new Outlook route, Options > Show fields	Not separately documented
Outlook for Mac	To show it on every message, select the Outlook menu > Settings > Composing, then turn on Show BCC field by default	Documented by Microsoft
Outlook for iPhone, iPad and Android	The compose screen has a Bcc box, per Microsoft's mobile recipient-suggestion page; Microsoft does not document how to reveal it	Field documented, route not documented

What Happens When You BCC Someone in Outlook

Each row below is a separate outcome. Read the reply-all row twice, because that is the one that exposes people.

Who	What they see or can do
Recipients in To and Cc	They cannot see who is on the Bcc line, and they cannot tell whether the sender added any Bcc recipients at all
Each Bcc recipient	Receives a full copy of the message. Other people who receive the message, including other Bcc recipients, do not see their address
Bcc recipients looking at To and Cc	The To and Cc names are visible to everyone who receives the message, which is why Microsoft notes a list name in To can be expanded by recipients
A Bcc recipient who selects Reply All	The reply goes to the visible recipients and reveals that the Bcc recipient got the message. In Microsoft 365, Outlook and Outlook on the web can show a MailTip warning before it is sent
You, the sender	You can see every Bcc name by opening the message in Sent Items
Junk email filters	Microsoft warns that many filters treat Bcc messages as junk, so a recipient who has not added you as a safe sender may find it in Junk Email
Recipients' own sorting rules	Rules that look for a distribution list name in To or Cc will not sort a message that has the list on the Bcc line

Can BCC Recipients See Attachments?

Yes. A Bcc recipient receives a copy of the same message, so every file you attach reaches them exactly as it reaches the To and Cc recipients. Bcc hides only the recipient's name from others. It does not create a lighter version of the message, so remove any attachment a Bcc recipient should not have before you select Send.

When You Should Use BCC

Microsoft's own Bcc guidance names three uses. The examples column doubles as a set of good examples of BCC emails you can copy.

Use Bcc to	Good example	Why it works
Keep a recipient list private	A job announcement sent to several potential applicants	No applicant learns who else was contacted
Stop a reply-all storm	Reply once to a runaway thread with your name in To and the distribution list in Bcc, asking people to reply to you directly	Further Reply All clicks reach only you
Protect addresses from harvesting	A club or parent-group update sent to people who do not know each other	Nobody can copy the full address list from the message
Send one update to a personal contact group	Your own address in To, the contact group in Bcc	Microsoft documents this exact setup to keep list members hidden

For a large mailing where each person should see only their own name, Microsoft suggests Word mail merge as an alternative to Bcc.

Use BCC in Outlook to send a mass email without exposing the list

This is the setup Microsoft documents for hiding a personal distribution list. It also answers the most common reason people search for Bcc: mass email to a group.

1. Open a new message and show the Bcc line using the table above.
2. Type your own email address in To.
3. Add the contact group or the individual addresses to Bcc.
4. Add a first line telling people why they are receiving the email and how to reply.
5. Check the total recipient count against your account's limit in the next section.
6. Select Send.

Putting the list name in To instead does not hide it. Microsoft notes recipients can expand a list shown in To and see every name and address.

How many people you can BCC in Outlook

Bcc names count toward the same per-message limit as To and Cc. Microsoft publishes these figures; your admin can set a lower one.

Account	Recipients per message (To + Cc + Bcc)	Recipients per day	Notes
Outlook.com with a Microsoft 365 subscription	500	5,000	Also 1,000 per day to people you have never emailed before
Outlook.com without a subscription	Lower than the subscriber limits	Lower	New accounts start with a low quota that rises as the account establishes credibility
Work or school account on Exchange Online	Up to 1,000; the admin center default for a mailbox is 500	10,000	Admins can set any limit from 1 to 1,000
Exchange Online, encrypted message	About 200	10,000	Applies when the message uses Microsoft Purview Message Encryption
Other providers (Gmail, Yahoo and others added to Outlook)	Set by that provider	Set by that provider	Microsoft's example is a limit of 100 addresses per message

A distribution group from your organization's address book counts as one recipient in Exchange Online. A personal contact group counts every member separately.

Microsoft states Exchange Online is not meant for bulk commercial mail such as customer newsletters, and points those senders to specialist providers.

BCC Versus CC: Which Should You Use?

Your situation	Use	Why
Colleagues on one project who should see each other's replies	Cc	Open copies keep the conversation visible
Customers, applicants or members who do not know each other	Bcc	It keeps every address private
A manager who needs a quiet copy of a routine update	Bcc	They are informed without being named to the team
Someone who is expected to reply	To or Cc	A Bcc recipient who replies all reveals they were copied
A meeting request	Neither works as a true blind copy	Microsoft states there is no way to add a true Bcc recipient to a meeting request

Best Practices for Using BCC in Outlook

Practice	What to do	What it prevents
Pave the way	Tell Bcc recipients to expect the message and add you to their Safe Senders list	The email landing in Junk Email
Think before you Bcc a distribution list	Put team lists in To or Cc when members sort mail with rules	Messages skipping the recipients' folders
Know your limits	Count To, Cc and Bcc names together before sending	A bounce for too many recipients
Use your own address in To for large private lists	Put yourself in To and the list in Bcc	An empty or exposed To line
Tell people why they are receiving it	Open the message with the reason and a reply route	Confusion and spam reports

What Not to Do with BCC

Do not	Why
Send unwanted bulk email through Bcc	Microsoft sets daily recipient caps to discourage it, and Bcc mail already draws junk filtering
Bcc someone you expect to answer the whole group	Their Reply All reveals they were a hidden recipient
Use Bcc to hide the content of a sensitive message	Bcc hides names only; the message itself is not encrypted
Assume a Bcc recipient is invisible to everyone	You can see them in Sent Items, and your organization's admins can search the Bcc field
Bcc a list whose members filter mail by list name	Their inbox rules will not fire

How to Add BCC Automatically in Outlook

Outlook for Windows has no documented user setting that adds a fixed Bcc address to every message. Two things Microsoft does document come close.

On a Mac, Outlook > Settings > Composing > Show BCC field by default keeps the line visible on every new message. In a Microsoft 365 organization, an admin can add a Bcc recipient to matching mail with a mail flow rule.

1. Sign in to the Exchange admin center at admin.exchange.microsoft.com with an admin account.
2. Go to Mail flow > Rules.
3. Select Add a rule > Create a new rule and enter a Name.
4. Under Apply this rule if, choose a condition such as The sender is and pick the mailbox.
5. Under Do the following, choose Add recipients > to the Bcc box and select the extra recipient. A distribution group is not allowed here.
6. Select Next, set Rule mode to Enforce, then Next and Finish.
7. Turn the rule on with the toggle in its details pane; new rules start disabled and can take 30 minutes or more to apply.

Microsoft notes the original recipients are not notified and cannot see the address the rule adds.

How to View BCC Recipients After Sending

Only the sender can see who was on the Bcc line. Recipients cannot see it, even whether one was used.

1. Open the Sent Items folder.
2. Open the message you sent.
3. Read the Bcc line in the message header; it lists every blind recipient.
4. Compare that list with the To and Cc lines to confirm no one private landed in the visible fields.

Quick BCC Checklist Before You Send

Check	Look at
Hidden people are in Bcc, not To or Cc	The three address lines
Your own address is in To for a large private list	The To line
The total recipient count is under your limit	The limits table above
Every attachment is fine for every Bcc recipient	The attachment bar
Recipients know why they are getting the email	The first line of the message
The content is safe to be forwarded	Bcc does not stop a recipient forwarding it

Is BCC Private Enough for Sensitive Emails?

Use Bcc to hide who received a message, not to protect what it says. For confidential content, use your organization's encryption or Do Not Forward protection as well. Bcc does not encrypt anything. The Bcc field stays in your Sent Items, Microsoft 365 eDiscovery searches can match the Bcc field, and any recipient can forward the message. Microsoft 365 offers Purview Message Encryption, S/MIME and IRM with Do Not Forward for content protection.

Common BCC Problems in Outlook and How to Fix Them

The Bcc field is missing in Outlook

Bcc is hidden by default, and the menu differs between new and classic Outlook.

1. In new Outlook, open the message and select Options > Show fields > Show Bcc.
2. If that menu is not there, you are in classic Outlook: select the Options tab and Bcc in Show Fields.
3. On a Mac, turn on Show BCC field by default under Outlook > Settings > Composing.

A Bcc mass email bounced or would not send

The combined To, Cc and Bcc count, or your daily total, passed your account's limit.

1. Read the bounce message for a recipient-limit reason.
2. Count the recipients, remembering a personal contact group counts each member.
3. Split the list into batches under your per-message limit.
4. On a new Outlook.com account, send smaller batches until the quota rises.
5. For recurring newsletters, use a bulk email service as Microsoft recommends.

Bcc recipients say the email went to junk

Junk filters often flag messages that use the Bcc line.

1. Ask recipients to add your address to their Safe Senders list.
2. Tell them in advance that the message is coming.
3. Put your own address in To rather than leaving it empty.

A Bcc recipient replied all and exposed themselves

Reply All sends to the visible recipients, which reveals the hidden copy.

1. Bcc only people who do not need to answer the group.
2. Tell Bcc recipients in the message to reply to you only.
3. In Microsoft 365, ask your admin whether MailTips are enabled; the Reply-All on Bcc tip warns them before sending in Outlook and Outlook on the web.

Team members' rules did not sort a Bcc message

Their rules look for the list name in To or Cc.

1. Resend or reply with the distribution list in To or Cc.
2. Keep Bcc for lists whose members do not need to see each other.

Frequently Asked Questions About BCC in Outlook

The first four questions come from real Bing searches; the rest cover the recipient behaviour those searchers ask about next.

How do I use BCC in an Outlook email?

Open a new message and show the Bcc line: Options > Show fields > Show Bcc in new Outlook, or the Options tab > Bcc in classic Outlook. Type hidden recipients on the Bcc line and send. Other recipients will not see those names.

How do I use BCC in Outlook to send a mass email?

Put your own address in To, add the contact group or addresses to Bcc, and send. Microsoft documents this to keep list members hidden. Stay under your limit: Outlook.com allows up to 500 recipients per message for Microsoft 365 subscribers, and Exchange Online up to 1,000.

How do I find the BCC function in Outlook?

It is hidden until you turn it on. In new Outlook it sits under Options > Show fields. In classic Outlook it is the Bcc button in the Show Fields group on the Options tab of an open message. On a Mac, Show BCC field by default is under Settings > Composing.

When should I use BCC in Outlook?

Use Bcc when recipients should not see each other, such as applicants or members who do not know one another, or to stop a reply-all storm. Use Cc when people need to see who else is included and follow each other's replies.

Can BCC recipients see each other in Outlook?

No. Microsoft states that other people who receive the message do not see whose address is on the Bcc line. That includes the other Bcc recipients. Only the sender sees the full Bcc list, in Sent Items.

Can recipients tell if I used BCC in Outlook?

No. A recipient cannot see whether the sender added any Bcc recipients. The exception is a Bcc recipient who selects Reply All, which shows the visible recipients that person received a copy.

What happens if a BCC recipient replies all in Outlook?

The reply goes to the sender and to everyone in To and Cc, so the hidden recipient is revealed. In Microsoft 365, Outlook and Outlook on the web can show a Reply-All on Bcc MailTip warning the person first.

Can I BCC people on an Outlook meeting invite?

No. Microsoft states there is currently no way to add a true Bcc recipient to a meeting request. Send the invite to the people who must attend, and use a separate Bcc email for anyone who only needs the details.

Can I see who I BCC'd in Outlook after sending?

Yes. Open the message in Sent Items; the Bcc line lists every blind recipient. Only the sender's copy shows it, which is why checking Sent Items is the way to confirm who was hidden on a message.