Is this an exploit of the email system of some sort? I receive a great deal of spam every day, and my accounts in Yahoo and Gmail sometimes show me spam emails from the future. Yes, the future.

Sometimes it will give me a day ahead when they send it, which could mean they are a day ahead via time zones, but sometimes I have also seen a week ahead, but rarely I find emails sent a month in the future.

Are these spammers exploiting a part of email that allows them to spoof the timestamp of the email? I have always been curious how they are managing to send me mail from the future.

  • 34
    In principle it's not much different from sending a letter through the post with a future date written on it.
    – bdsl
    Jul 29, 2015 at 11:33
  • 7
    I noticed that many years ago, and then that use disappeared. I suppose spammers wanted to come first in your list of emails, but then people figured it out and deleted all mail from the future without ever looking at it (I certainly did) which made this useless. It will probably come back every ten years.
    – gnasher729
    Jul 29, 2015 at 12:18
  • 6
    Did you check your clock to verify that you aren't in the past? This is a basic use of headers known since 20 years 😄 !
    – dan
    Jul 29, 2015 at 13:05
  • 16
    I made this comment 3 weeks from now.
    – Jon Hanna
    Jul 29, 2015 at 16:30
  • 18
    Have you offended any time travelers? Jul 29, 2015 at 16:53

3 Answers 3


That's not an "exploit", rather the way e-mail works.

Datetime, sender, receiver, and all other headers of an e-mail message can be set by the sender to whatever value he wishes; mail protocols make no security check on them. Hence, spoofing the sender of an e-mail (as spammers, scammers, and phishers often do) it's a child's play.

As Priyank correctly said, if you look at the full headers of the message you received you'll see that only the first hop (the sender) bears a date in the future; all the other hops (the MTAs between the sender and you) are correctly timestamped with the actual date.

  • 15
    unless it isn't a real spamm mail from the future. in that case the other time stamps including his own ISP's one would be from the same date :'D
    – Zaibis
    Jul 29, 2015 at 11:34
  • 1
    @zaibis unless it is.
    – DRF
    Jul 29, 2015 at 19:49
  • 2
    @DRF yeah thats what i mean. I'm not a native speaker and didn't knew "unless" itself contains allready the "not" in its meaning.
    – Zaibis
    Jul 30, 2015 at 6:39

It is kind of possible.
Suppose you change your system date/time and use a local client like Outlook to send an email, then the receiver will see the changed time. But in the email headers, the actual time of the email when it was received by the server, will be mentioned.
But if you are using some email service on your browser, then the actual time will be seen by the receiver.

Another possibility, which would be EXTREMELY rare, is that the time on the mail server is wrong.

In your case, try checking the headers of the spam emails.

  • 3
    This is fine but is any significant amount of spam sent by using mail clients such as Outlook? More likely, the source is a script, which either sets a specific time or is running on a machine with an incorrectly set clock (probably, actually, some random person's computer on a botnet). Jul 29, 2015 at 10:53
  • 1
    Well, as dr01 mentioned, it is also very much possible to edit the email headers. Did you check the email headers?
    – pri
    Jul 29, 2015 at 10:58

Most messaging systems do allow drag-in/out copying of emails from the client to the desktop. So if you want to send spams with any dates you want, there are various options.

Actually you can quickly code a mass mailer in Python and change automatically whatever parameter you want in the headers, including time (how to change email's header programmatically)

An other option is that you keep your previous mass mailer in Python (I mention Python because I experienced it a lot and it fits very well for such situations) and execute it in Windows OS virtual machines and change the system date automatically to whatever you want so that it will appear in the header of your spams (how to change system date and time programmatically)

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .