How do I view the list of BCC'ed recipients on an email I've received?

The list of BCCed recipients is not included in emails, so there is no way of determining if and who else the email was sent to.


I want find the list of “undisclosed recipients” of the email I’ve received in Outlook. Is there any way?

“Undisclosed recipients” is often placed in the “To:” line by some mailers when the email being sent has no entries in the “To:” or “Cc:” lines. The sender has used the “Bcc:” feature of email to send the email to one or more people, without revealing who they are.

So, how do you find out who they are?

You don’t.

That’s what “undisclosed” means. The information about who the email was sent to is not included in the email. There is simply no way of determining if it was sent to anyone else and if so, who.

Now, to be complete, I do recall hearing about some old email programs – and we’re talking ten or twenty years ago – that got the whole concept of Bcc: and undisclosed recipients wrong. They included the BCCed recipients in headers that everyone could read if they knew how. But that was a serious bug and has long since been resolved.

Today’s email programs simply don’t disclose undisclosed recipients.

It would be wrong to do so.

There are 81 comments:

  1. PC Reply



  2. Leo Reply

    If you recieve an email, you CANNOT see who was BCC’d on it. Period. That information is *stripped* from the mail before it is sent.

    If you are the *sender* of an email on which you BCC’ed people, the some email clients will simply preserve that information in your copy of the mail in your sent mail folder.

  3. steve Reply

    How come I can’t see the bcc list on e-mails that I’ve SENT out? Not received from other people, I know that those lists are meant to not be seen. But what about when I want to go back a check bcc addresses of e-mails I sent out?

  4. Leo Reply

    That’s entirely dependant on the mail program you use. Some save and show the BCC line on sent mail, others do not.

  5. dora Reply

    Any idea how to retrieve the bcc: recipients in an outgoing mail in the Sent folder of OE?
    We are using IMAP.

  6. Izzy Reply

    How do I view a list of BCC’ed recipients that I’ve copied into an email in Yahoo Mail? It’s driving me mad as I can never remember who I’ve sent emails to!


  7. Alok Reply

    If you have sent a message to Undisclosed Recipients. And want to see whom you have sent the mail after sending it. Search by Message ‘Subject’ In Google Desktop.

  8. John Reply

    Thanks and a tip of the hat to Roy Rudder for providing the answer to me. I’ll pass it along here:

    Just go to the sent folder and right click the email and click properties.
    Then click the details tab.

  9. cornwell Reply

    how do i get the list of undisclosed recipients on emails that i have received in my email box

  10. chad Reply

    Leo – if the BCC list is really stripped when I receive an email sent to me via BCC, how come when I ‘reply to all’ – ALL of the BCC list gets my reply?

    The information is in there somewhere….

  11. Leo Reply

    Then there’s a bug the sender’s mail program, or the BCC wasn’t really a BCC. (CC maybe, but not BCC). A reply to a message where people are BCCed should NEVER go to the originally BCCed recipients.

  12. Mark Reply

    A few years ago when I was with a different agency, I could have sworn there were instances where email recipients had replied to emails, that had Bcc: recipients, using the Reply All feature and had their reply go to the Bcc: addressees, as well. or was I just dreaming?

  13. Leo Notenboom Reply

    I’m told there used to be a bug in Outlook Express that included the BCC recipients in the message headers. That, as I said, is a bug and has been fixed. Perhaps that’s what you were remembering?

  14. harpal Reply

    I’m using outlook express. Been told that every email that i send out is been Bcc to particular person. How do i check who d person and how to bypass it from bcc to that particular person.

  15. Pushkar Reply

    Actually some e mail programs can reveal the BCCed persons. As a sender u can always see the BCCed person but the catch is when you are the recipient of a BCCed mail and you want to know that, if the sender has BCCed the mail when you are “TO”.

  16. Carl Reply

    I have a reverse problem: trying to check or reveal BCC recipients as a Sender for a message I Sent that a client claims they didn’t receive. I have the original message in an OE folder. I tried File>Properties>Details>Message Source, but it shows no BCC recipients, only my email as blind “To:”. I know others received this from their responses. Any ideas?
    Thanks, CF

  17. steven Reply

    Hi, this is easy. Just hit reply all after you receive a email, then you will see all the To, CC and BCC recipients.

  18. Leo Notenboom Reply

    That’s simply not true. BCC’ed recipients won’t be present.

  19. Dinesh Jiwankar Reply

    How do we see BCC recipients on an email which we received from some one outside our LAN.

  20. Leo Notenboom Reply

    Hash: SHA1

    Read the article. You don’t.

    Version: GnuPG v1.4.6 (MingW32)


  21. Ian Smithdahl Reply

    It’s my understanding that on a server-to-server communication level, only one copy of an email is sent regardless of the number of recipients in the to, cc and bcc fields. *If you have access to your mail server* you can open up those raw email logs and look at the bcc fields. Your local mail server strips the bcc field info when it sends it to your account; so if you don’t have root access to that mail server, then you don’t have access to the bcc, at all.

    At least as far as know.


  22. Kyle Reply

    I want to clarify that even at the server level, you cannot view BCC information, and I am talking about when logged in as root and using cat to view the e-mail file.

    The following was BBC’ed to three addresses, yet it is impossible to tell who the other two are from the message.

    To be sure, you cannot even determine if the message was BCC’ed to anyone at all.

    cat output follows (with personal information removed):

    Received: from ([])
    by — (—)
    for —@—;
    Fri, 13 Apr 2007 12:10:00 -0700
    Received: by with SMTP id 68so944227wra
    for ; Fri, 13 Apr 2007 12:09:59 -0700 (PDT)
    Received: by with SMTP id i7mr1074974wam.1176491398758;
    Fri, 13 Apr 2007 12:09:58 -0700 (PDT)
    Received: by with HTTP; Fri, 13 Apr 2007 12:09:58 -0700 (PDT)
    Date: Fri, 13 Apr 2007 12:09:58 -0700
    From: “Kyle —”
    Subject: —
    MIME-Version: 1.0
    Content-Type: multipart/alternative;

    Content-Type: text/plain; charset=ISO-8859-1; format=flowed
    Content-Transfer-Encoding: 7bit
    Content-Disposition: inline

    Content-Type: text/html; charset=ISO-8859-1
    Content-Transfer-Encoding: 7bit
    Content-Disposition: inline


  23. Dennis Reply


    I want to add the Bcc option to my outgoing email, but I can’t find anything that gives me the option to add it.


  24. Leo A. Notenboom Reply

    Hash: SHA1

    That depends entirely on the email program that you use. Check the
    documentation for it.


    Version: GnuPG v1.4.6 (MingW32)


  25. Crys Reply

    This is an opposite problem:

    I sent an email in Hotmail to a mailing list I have. I desperately need to see the BCC addresses I sent to but can’t find a way. I tried clicking on the message, it only shows To: and CC: not BCC. HELP!!!

  26. birundha Reply

    i have tried hitting “reply all”.But it’s showing only the mail ids in the “TO” list and “CC” list only.

  27. Janarthanan Reply

    Ok, If I am sending a mail to others by using BCC, How to see those mail-ids later in sent folder ?

    Pls reply to this.

  28. Leo A. Notenboom Reply

    Hash: SHA1

    It depends ENTIRELY on the email program you are using. With most YOU CANNOT.
    Basically if you look at the sent message if they’re not visible, then they’re
    not available.



    Version: GnuPG v1.4.7 (MingW32)


  29. Jack Frost Reply

    It depends on your mail client. Don’t trust Outlook. DO NOT do reply to all if you are not certain.
    Most clients will let you see the actual email text that comes in (that is all that email is, text, binary stuff is encoded as text).

    At work I use Outlook for work only, and my private gmail, through a proxy I run on my home server over SSL for any personal emails.

    Play it safe, don’t say things in a corporate email you would not want EVERYONE to see.

  30. Ramona Reply

    I am totally confused because I use the bcc all the time. I sent a message using bcc last night and when a recipient replied it showed my original message with everyone’s email addresses showing in the “To” block. Why did this happen? Now I’m scared to send to multiple friends because of this glitch. I’m using Outlook 2003.

  31. Justin Reply

    I use thunderbird on my home pc for mail. I received what look like a scam email from RBS. Thunderbird also flagged it up as a scam and displayed the BCC list for the other 20 users the scam email was sent to. If BCC’s are indeed undisclosed to receiving mail servers how is this possible?

  32. Krissy Reply

    At what point is the BCC information stripped from the email? Do two separate packets go out completely stripped of the information, or does it happen at the mail server/ISP? How do spam programs know (if they do) that there is a long BCC list?

  33. Leo A. Notenboom Reply

    Hash: SHA1

    Justin: then the sending mail program was not handling BCC
    properly or we’re not really talking about BCC.

    Krissy: the BCC information is stripped off by the sending
    program. It tells the mail server who to send the mail to,
    but does NOT include the headers that would normally be
    included in the message that would also contain that list.


    Version: GnuPG v1.4.7 (MingW32)


  34. R Reply

    In Yahoo – if you want to see the BCC list for something that YOU sent.. Right click on message – choose “Veiw full headers”. This is for the new Yahoo mail – not sure about classic yahoo mail.

  35. wtkjd Reply


    There is a known bug in Exchange 5.5 through 2003 SP1 that if a non Outlook MAPI email client is used to forward or reply to an email with BCC recipients, the BCC recipients will be revealed. How do you explain that in light of your statement that the BCC information is stripped off by the sending system? Do you have reference for a kb article or otherwise that defines this in MS Exchange? This is a mission critical issue for me – thanks for any insight you can offer.

  36. Leo A. Notenboom Reply

    Hash: SHA1

    I’m not sure what I’m supposed to explain. You said it
    yourself, it’s a bug, it’s not supposed to happen. BCC
    information should never make it past the sending server,
    and ideally never even leave the email client.


    Version: GnuPG v1.4.7 (MingW32)


  37. Meredith Reply

    In Outlook Express: If you are the sender of the email with BCC recipients you are the only one able to see that list by:
    Right clicking onto the email in the Sent folder, select Properties. Click on the Details tab and the list of BCC’d recipients will be shown to you.

    It is always there for the SENDER only. Recipients are not stripped.

  38. Bernard Winchester Reply

    I have Outlook Express and need to see the BCC recipients of e-mails I have sent; I have tried the above method of checking the details tab on the properties of the e-mail, but it doesn’t work; the BCC remains hidden. Perhaps Microsoft has removed this entry of the panel in a recent update. When you can’t see to whom you sent your own messages, data protection has surely gone too far…

  39. Steven Potter Reply

    In Outlook 2003,
    Open the sent message from the Sent folder;
    View => Header (toggles on/off)
    bcc will appear

  40. Chris Reply

    Leo, I think you are not answering the question that was asked, “I want find the list of “undisclosed recipients” of the email I’ve received in outlook. Is there any way?”. Take a look at following link

    Fascinating. First, let’s be clear: this is fairly irrelevant to most people, however, as it applies ONLY to encrypted email.

    The paper outlines a flaw in how many mailers create encrypted email. It’s not a direct exposure of email addresses, but rather encryption tokens that could be traced back to email addresses.

    And to be even clearer: it’s a flaw in the system – BCC is not supposed to be exposed.

    Thanks for the pointer.

    - Leo
  41. mark raulston Reply

    I understand that you can’t see anyone in the bcc: list if you are the recipient, but what about if you’re the sender?

    I sent an e-mail to a long list of recipients in the bcc: field but forgot to include an attachment. how can i bring back up the e-mail, add the attachment, and resend it to all the same recipients?

    Thank you!

    It depends on the email program you use. Basically, just open the sent mail, and it’ll either be there or it won’t.


  42. Bob Reply

    You say: ‘The information about who the email was sent to is not included in the email.’ Therefore it can’t be delivered to me. End of ALL SPAM – YIPEE!!!

  43. Frank Reply

    I’m sorry to tell you that you are wrong. The RFC 821 describing the SMTP protocol sates clearly that the addresses of the receipients are part of the “DATA” field (RFC 821, Page 5). The “DATA” field is sent to all receipient-SMTP agents. Having access to the SMTP-agent gives you also access to the full list of receipient users, independently if they are To Cc or Bcc users. Most of the Mail Systems handle the received mail in order to deliver mails without the whole list of Bcc receipients. But how can you rely on a statement that says “most of the systems do so” ?
    If you want to be sure that the receipients receive the mail without getting the possibility to know who else received the same mail then you must use a mail distribution program that sends one mail to each of the receipients in a given list.

  44. Mike A Reply

    I have more than one email address. How can I tell which one an email was sent to. I use Outlook 2007. If an email address gets too much spam, I like to kill it off, but I need to know who is using it.

  45. Judy Fegley Reply

    The article and comments were helpful and I know how to use “undisclosed recipients” and the bcc field but is there a way for me, the sender, to see who I actually sent it to after it’s gone? Thanks!

    That depends on your email program. Some will save and show you the BCC’ed addresses when you look at the message in your Sent Mail, others will not.


  46. George L. Berish Reply


    But what if I am a BCC: addressee? Right now when I receive that type of email its confusing, because it shows a TO: (who is not me) but no BCC: (who is me). And I can’t figure out how (or if) I can get my received email to show me as a BCC: so I’d know why I received an email addressed to someone else.

    You cannot. That’s the whole point of BCC.


  47. Scott Reply

    I have multiple e-mail accounts and I organize my e-mail partly by the e-mail account it was sent to. However, for e-mails I received that I was bcc’d Outlook doesn’t by default show the account the e-mail was sent to and won’t organize the e-mail properly. I can’t even find a way to view the header to see the account. I have to use my web e-mail client to view the header to see the account. Is there a way to get Outlook to organize these e-mails?


  48. mark Reply

    i once sent the same email to multiple companies and put all their emails in the BCC so the second day they phoned me and asked if i accidentally sent it to those companies and when they replied it showed that all the other email addresses where revealed . how come they can????

  49. karishma mehra Reply

    Wud like to know how to see the BCC in recieved mails from one particular person as I think that person is playing up I am sure there is a way to find out

    There is not a way to find out. That’s the point of BCC.


  50. Steve Crowhurst Reply

    Have you tried Reply All… not that you would reply to all, you just want to check who was Bcc’d. Look in the TO: line for new / suspect emails. It works for me using Outlook. If the Bcc’d is a group… then it’s a no go. You may uncover the group name such as Sales Team West… and that’s it. Have a colleague send you an email with a Bcc and then see if the Reply All works for you.

  51. marty Reply

    Do spammer’s use BCC? I get a lot of emails from addresses other then mine that are spam? How does the receiving mail server know where to deliver the mail if the BCC is stripped from the sending server?

    Spammers use BCC all the time. The way email servers work they know where to deliver it, even if the BCC line is stripped from the email that’s delivered.


  52. arunesh Reply

    If i select reply to all than does it goes to BCC recipients also ?



  53. joe Reply

    can the IT personal find out who was bcc’d on an email?

    Not directly, no. An IT person at the email provider you’re sending email through might be able to see a series of emails sent at the same time and infer that they were recipients of the same message.


  54. Rusty Reply

    Here’s a little twist. In Outlook 2003, you could set up a rule for a message to behave a certain way depending on whether the message was sent only to you, and this would let you determine if a message was Bcc’d or not, even though you couldn’t see the recipients. With Outlook 2007, there doesn’t seem to be a way to do that directly.

    Is there a way you can think of to simply determine whether the Bcc field was empty or not? Or in other words, determine if you’re the only recipient in the message?

  55. Sandy Grambow Reply

    How do I view the list of bcc recipients on a email I sent out? I want to check to see who I sent the email to.

  56. Wayne Jordan Reply

    IT personell can find out who the BCC recipients are. Having done forensic analysis of how information was “leaked” from a company I have used this information myself. Required approval at the highest level of the company to interogate the archive and then the searches had to be properly specified.

  57. Joseph Rothwell Reply

    “Today’s email programs simply don’t disclose “undisclosed recipients”.
    It would be wrong to do so.”

    But it is perfectly acceptable for me to constantly receive mail that doesn’t have my email address shown, so therefore must be bcc’d? I don’t agree with blinding; I can’t imagine it being used, proportionally, very much when compared to spammers. But oh well. I guess it’s worth it for those couple of people who do use it for real purposes.

    Something that would be good, is if the big providers like gmail were to create an option to block incoming emails that were bcc’d to a user, unless they come from a trusted source (whitelisted)

  58. Henry Reply

    Quote – It would be wrong to do so.


    Why? How does such a statement apply to people like us here in Australia…Remember you have made this statement to the WORLD. There is NO general right to privacy in Australia and using a BCC is a reverse denial in that the user is impossing their own privacy with NO right to do so !!

  59. Mark J Reply

    Leo isn’t talking about legalities, he just saying that if a program says it will hide the recipients’ email addresses, it will do what it says.

  60. Idee Reply

    Leo, you’re absolutely right about not being able to see who the other BCC recipients of an email are; but if you have Outlook Express and you want to see who you sent your BCC message to, go to “Sent Items” and right click “Properties”. Then select “Details”. The names (and addresses) of all your BCC ‘s are displayed. No problem. I don’t know about other programs.

  61. Shyam Reply

    Leo, I can see the list of email addresses of the undisclosed recipients for 2 seconds on my iPad, everytime I open that email, before it turned into the undisclosed recepients name. If they can be seen, there must be a way extracting them, I strongly feel.

  62. upk Reply

    shyam – what u mentioned is interesting.
    can u gv more dtails of what u r using to chk the email ( when u see the bcced addresses on your ipad for a couple of secs)

  63. Tim Reply

    When searching for a surname in Outlook Inbox emails appear in the search results but there is no mention of that particular surname anywhere within the email. Is this potentially pulling out surnames of recipientss that we BCC’d?

  64. KevinG Reply

    Leo, if an e-mail was sent to me and someone was Bcc’d in it and I reply to all, the person that was Bcc’d will also see my reply. How is this possible if your statement, “The information about who the email was sent to is not included in the e-mail”, is true? The only way I can see that the Bcc’d person will get my reply is if his details are somewhere in the incoming e-mail that I’m replying to.

    If you an email which originally had BCC’ed recipients, a Reply-All will NOT reply to those recipients. Their information is not included in the copy of email that is actually sent. (If it is happening, then there is a serious bug in the email system of the individual who sent the email in the first place.)

  65. Mark J Reply

    @Kevin G
    If you reply to all in an email with BCC, the people on the BCC list shouldn’t get a copy, as their name and address info doesn’t appear on the emails sent. I can only imagine that happening if there were some bug in the email sending program or website. I would say the same for the case where the BCC list appears momentarily on the iPad. BCC is not supposed to transmit any receivers’ information to any of the other receivers.

  66. KevinG Reply

    @Mark J
    I was under the same impression as you, but this is what happened that made me post a comment:

    One of my suppliers sent me an e-mail and Cc’d someone else in her organisation, so I automatically “Replied to All” with my response. Just after that I received and “Out of Office” from her manager, but he wasn’t addressed in the e-mail as far as I could see, so the only way I could have received an “Out of Office” from him was if he was Bcc’d in the original e-mail that I replied to.

    That’s not the only way. One of the email addresses you DID see (in To: or Cc:) could, for example, be auto forwarding to the manager. I’m sure there are other explanations. Again, BCC information is NOT part of the email you receive.

  67. Logan Reply

    Leo concerning your sabbatical observance are you getting paid to read comments if not how is that violating the law? Jesus performed miracles and help people in need even on the 7th day, Saturday.

  68. Bob B Reply

    Regarding viewing BCC’s that have been sent. MSN Internet Explorer 11.
    Go to sent mail, click on the small down arrow up by the sent by name, listed will be all of the BCC recipients below.

    • Leo Reply

      It’s not a function of using Internet Explorer, it’s a function of the mail service or program that you use. Apparently you’re using MSN … which implies

  69. Luke Reply

    Fact is, if you save an email that contains BCC addresses from something like outlook to your desktop, and then open it in a text editor, you can easily just get the BCC email addresses out of this object as it contains all the BCC emails as plain text… Completely discredits your ‘cannot see them’ theory.

    • Mark Jacobs Reply

      That’s simply not the case. BCCs are not in anyway visible to the recipients unless for some reason, there was a bug in the email program or webmail sending routine.

    • Leo Reply

      This can work on emails you’ve sent, but does not on email’s you’ve received. If it ever does the sending email program is broken.

  70. TARUN SETHI Reply

    How do I view a list of CC’ed recipients that I’ve copied into an email in OUTLOOK 2007? It’s driving me mad as I can never remember who I’ve sent emails to!

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