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Can I prevent my mail from being forwarded by others?

Is there any way I can keep from letting people forward emails I have sent them onto others?

In short: no.

And it can get even worse. Much worse.

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Once you’ve sent email, it’s gone and you lose all control over it. And by all control, I mean:

  • You cannot “un” send it, or prevent the recipients from getting and reading it.
  • You cannot reliably tell whether or not the recipients have received it.
  • You cannot reliably tell if the recipients have read it, deleted it or forwarded it.
  • You cannot prevent them from forwarding it, copying it, changing it, or doing pretty much whatever they want with it.

Note I said “reliably” in a couple of cases. There are technologies, such as “bugs” or simple image tracking for HTML formatted email, that can sometimes allow you to tell that an email has been opened. This is not 100% accurate, and hence cannot be absolutely relied on, mostly because modern mail clients often have the required functionality turned off by default as a security and privacy measure. And “opening” an email does not necessarily mean that the email was actually read or even seen by anyone.

But in regards to your question, it’s the last one that should cause us all to think.

I’ll put it more clearly: you cannot prevent someone from forwarding your email, and you also can’t prevent them from changing it before they do so.

Get that? Not only can they forward your email, but they can change what your email says. When someone forwards an email, that email simply becomes the body of a new email, that can be edited before hitting send. And by edited, it could be as simple as changing a “yes” to a “no”, an “I love you” to a “get out of my life”, or perhaps “the boss is a genius” to “the boss is an idiot”.

Peeking at a locked document You get the idea. If you were concerned about your email being forwarded, you can be even more concerned now. You really do need to trust your recipients.

So, if email is such an unreliable medium, what can you do? Well, the simplest first step for this particular issue is to save all your outgoing email. That way you’ll have a record of what you really said. Second, don’t say anything in email that you wouldn’t want to be made public, and when things get “close”, make sure you’re only emailing it to someone you really trust.

There are technologies such as cryptographic message signing that will allow message tampering to be detected, but currently they’re used mostly only by some businesses and the very tech savvy. To be honest it shocks me how much sensitive information is transmitted in email without any protection whatsoever (other than the silly disclaimer that boils down to “if this message wasn’t intended for you, forget everything you just read”).

I’m hopeful that over time these types of security solutions will get easier, and more common.

And the bottom line is that if someone can read your email, they can still forward it, or copy/paste it to another email, and send it to anyone they choose, one way or another.

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41 comments on “Can I prevent my mail from being forwarded by others?”

  1. Here’s an interesting idea… put a copyright statement in your signature file, stating your e-mail is copyrighted 2006 by you and forwarding is prohibited without your express permission.

    According to…

    …as long as you file the copyrighted material with the Library of Congress and pay the copyright fee within 3 months of “publication” (i.e. sending the message), you can sue the person who forwarded the e-mail for $150,000 in statutory damages and attorney fees.

    The tricky part is “publication”.

    Now, IANAL and from what I’ve read, this is still just a legal *theory*. Whether sending an e-mail to an individual could constitute “publication” is still up in the air and could go either way. It might be worth the $30 to send an e-mail to someone, then file a copyright application for it and see if the Copyright Office approves the application.

    If the sending of an e-mail to one person did get legal status as “publication” of the e-mail, it would certainly protect your e-mail from being forwarded by any U.S. recipient if you put the copyright notice in it.

    If they forwarded it that day and it caused you harm and/or embarrassment, you could call your lawyer and file a $150,000 suit.

    – Greg

  2. a hacker went into my pc and foward message and got all my contact…what can i do to stop this? I already change my password, is this is enough? plz tell me what I have to do?? I am worry if he have acsess to my file.



  3. If you use Outlook 2003 there is the ability to request read receipts and recevied receipts.. but most of these are diasbled now because of spam and virus vulnerabilities. Bascily things being used maliciously…. so yes.. the capabilities are there for some of the aforementioned inabilities, nevertheless I would look around in the options of your message you’re sending and make the message expire in a short amount of time, that way it doesn’t get forwarded after a certain amount of time. I may be wrong, but i think it works without an exchange server… Leo.. ya or nay?

  4. There’s no way to make a standard e-mail message self-destruct without the receiving party essentially agreeing to it by using software that accepts and executes the self-destruct instructions.

    • Actually yes there is a way.. Send you email as an html email with the “letter image” being stored on your website or other specified image storage site then after an appropriate time delete the image!
      Note: This doesn’t work with embedded image but true html email.

  5. From what I can tell that only works with Microsoft products – might be an ok corporate solution (Exchange in the corporation could do some of these things), but not for the general public.

    And ultimately, anything the recipient sees on the screen can be captured and printed, and possibly forwarded on.

  6. Think someone is using my email in an outside program. I change my password alot. But lately I am getting return email from a few address that are not mine. this is part of the message.
    “This is an automatically generated Delivery Status Notification. Unable to deliver message to the following recipients, due to being unable to connect successfully to the destination mail server.
    Outlook user = login to hotmail website”
    I use outlook. but NOT on this account. From comments I see that I have been hacked. IS this true? and how do I prevent this from happening, BESIDES changing my password daily or weekly?
    Thank you for your time.

  7. There is a possible solution.

    Create a form using the standard Outlook email message. Edit the Properties of the “To” field to include a validation (such as [To] = “recipients_email”), or, simply disable Replying, Forwarding, etc. in the form. Save the form, then use it to send emails.

    Food for thought. 🙂

  8. Hardly. There’s nothing to prevent someone from copy/pasting your message into a new message. Or for another mail program that doesn’t use forms to ignore everything you’ve set up and simply allow forwarding.

  9. Saffe does pretty much all of the above (prevent forwarding, make difficult to copy/modify,…). The main drawback is that your recipient has to click on a link to view your message. Other than that it’s basically used like regular email. Check it out

  10. Someone keeps hacking my email and then giving my password back. So that I’m able to use my email and then at other times I’m not. Can you tell me how to make my hotmail secure so that the hacker cannot hack it again? Please reply quickly before the hacker hacks my email again!

  11. I read the article and comments, but nothing seems close to what happened to me. This is everyone’s worst nightmare: My ENTIRE hotmail account of 1,600 e-mail messages (received since 2003) was somehow recently sent to a friend’s PC! I was working on another friend’s computer sending out notices of an upcoming event. Oddly,here was no reply button, so I sent each individual an email by going to file and send. A weird box came up that warned of either a virus or worm, but also stated it could mean I was simply sending out repeated text. The warning asked if I still wanted to send (which I did, as much of the text was indeed repeated text of the same event). Soon thereafter, three of my friends reported receiving emails from the owner of the PC with strange attachments. The owner, an honest person, denys this. As mentioned, only one of these friends (boyfriend) also received my WHOLE email account with access to all my private mail! Does it sound as if my account was hacked into, or the PC I was using, or perhaps the PC of the recepient of my 1,6000 private emails? Needless to say this is a nightmare. Is there any possiblity the receiver of these e-mails could even be responsible? How do I find out? Who should I report this to? My privacy was grossly violated! Thanks.

  12. I recently received a spoof email that I can NOT forward to the spoofed bank’s investigation section or anyone else (not even to myself). I can forward any other message to anyone I like. What’s going on?

    Hash: SHA1

    No way to know without more details of how it’s failing.



    Version: GnuPG v1.4.7 (MingW32)


  14. I concur 110% w/ Leo… Tried a few methods offered directly by MS for Outlook 2003 & Outlook 2007. Neither was even close to being foolproof, even when sending to another person internally. As mentioned all too often – once the message leaves your server, ALL BETS ARE OFF. Someone out there is going to find a way to copy and/ or forward your message.

  15. In our business we type sensitive messages and output them as attached PDF’s. As they are image type PDF’s it makes it a bit more difficult to tamper with.

  16. Lotus Notes does indeed prevents copying. We use it at Office and have found it works ! Leo- what comments ?

    I can copy anything you can read by taking a screen shot. I’m guessing if you send email to someone who’s not using Notes it can still be forwarded/copied no matter what you tell Note.

    – Leo

  17. Hi,It is possible to make sure your mail is not forwarded provided you are using outlook.But if you are using yahoo or gmail,it is not possibe

    Not true. Doesn’t matter what email program you use, if you send email to someone they can forward it on to someone else.


  18. I wanted to answer the question being asked about regarding forwarding emails. There is a way in Outlook 2007 on preventing the email from being forwarded. I was not sure if this question is being asked of a previous version or not. In Outlook 2007, the instructions are below. I recall in Lotus years ago the ability to stop forwarding as well as printing of the email.

    Open and create the message,
    Click the Office Button,
    Go to Permission and click Do Not Forward

    In Outlook 2003, you would have to create a Form and the problem with this is that both the sender and receipient would both have to be using Outlook.

  19. In Groupwise from Novell, we can unsend email, which comes in PLENTY handy if you “type angry” as Bill Murray would say. If they haven’t opened it, and they don’t have automatic forwarding turned on – it is gone.

  20. Leo, can you address the comments that note the anti-forwarding capabilities in Outlook 2007?

    Sure: I’d bet that if the recipient was using a different email program they could forward the mail – and even if somehow that were not the case I could “forward” the mail by taking a screen shot of the email while viewing it, or printing it to a PDF, and forwarding that instead. I stand by my statement – there is no way to completely prevent an email from being forwarded.


  21. I agree with Leo – there are so many different ways to pass on the information.
    Even if you cannot print it, or screen capture it, if you can read the e-mail what’s stopping you opening a new one and re-typing it?
    Even if you use an old-school cypher on the content (requiring the recipient to know the code you are using), nothing stops them from forwarding the uncoded translation.

  22. This is along the same lines…I just noticed that a very private email of mine which had been going back and forth had R: Re: Fw: R: Re: Re: Re: Re: in the subject line…does this mean that somewhere in there what I wrote was really forwarded????

    Probably. “R:” or “Re:” is pre-pended to the subject line by many emails when someone replies to a message. “Fw:” or “Fwd:” is pre-pended when a message is forwarded. The message has generated several replies and forwards it appears.


  23. What if someone puts a legal clause in thier email prohibiting anyone from copying, reproducing, forwarding without thier consent? Is this legal to do that over the public airways? If so, this sets a huge precedence and has huge implications. Steve

    I’m no lawyer, but I always think those are kinda stupid. “If this wasn’t meant for you don’t read it” always cracks me up. Too late. Remember that what you are technically capable of doing (anyone can copy or forward any email at any time) is completely separate from what people can sue you for (just about anything).

  24. I use the email tracking service’’. While not 100 % as mentioned by Leo, it does a reasonable job. For example, if you have a repeat distribution list and a person on the list consistently takes an excessive time to open his email, then you have learned that email is not the way to reach him if timeliness is important. If you believe that recipients should be opening your mail withing some period of time you consider to be reasonable, you can see if that has happened by checking the percentage of opened emails. Again, I agree with Leo that we are not dealing in absolutes here but the responses do give you a good sense of the success of your distribution.

    If the tracking information provided shows a number of forwards, then you also know that the recipient has taken the message seriously. Also, if you had intended the message to be private and there are a number of forwards shown, this is another story.

  25. I have always been very careful with e-mail. My “mantra” if I would feel comfortable seeing this e-mail in a court deposition, then I push the “send” button.

    Because it’s true: think about Oliver North in the Iran-Contra scandal in the 1980s. He thought that deleting his e-mails from the PROFS system would save him from the consequences of his actions. Of curse, it didn’t because e-maisl were recovered, and this was with what was available in the 1980s.

    Also, in the past, when I used Outlook for e-mail, I would send with “message received” and “message read” options for anything that I considered worthy of an audit trail. And for the very most important (of which there were few) I would print those e-mails with messages &keep them in a file. Sort of like belt and suspenders worn at the same time.

  26. How about this… No matter what technology you may or may not be able to use to stop copy/paste, forward, screen-capture, etc., nothing you do can prevent someone from simply using a camera to take a picture of the computer screen.


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