If I set the system time of my computer to a datetime in the past and send an email then the recipient will see that time as send-date-time. I think the recipient has no chance of detecting the real time the email was sent (sure, only if he wasn't online after that time).

I tested that with Thunderbird.

How can I change the send-time without having to change the time of my computer?

  • Good luck with that. Time stampety-stamp-stamp on every handoff along the way. Truth Fabrication in email... interesting concept but full of fail in implementation. – Fiasco Labs Sep 27 '13 at 6:17
  • I have had spam emails with false dates once.. and once I had an email with a wrong date/time. With the spam emails with false dates, I don't recall the year but I think it may have been a very early year, so as to get to be my allegedly oldest emails(thus having some strange prominence). And the case of an email from a friend having the wrong date/time it must've been set wrong on the server the email went through. (I don't recall for sure but there may have been a few times there and only the one was funny - which makes sense). But the email client used the funny one. – barlop Sep 27 '13 at 6:26
  • @FiascoLabs so following on from ^^ comment.. sure if they check the headers they'd see. but in those instances, but for just the email client or web interface to pick up the wrong date/time is not impossible. OK for a prank on somebody that doesn't know to check headers. Not ok for a crime! I don't know whether it takes the time from the SMTP server or the POP server receiving.. If the former then you could, would be a funny project. note- I don't recall if the spam one I got was a future one that stuck as new, or a past one that stuck as the first email. or if i got both. – barlop Sep 27 '13 at 6:31
  • Use a virtual machine maybe? Then you could have any date time... As for stamping, each server has it's own rules... – Dave Sep 27 '13 at 7:09
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    Barlop said "But the email client used the funny one." I've seen Thunderbird do just that -- display the date/time from the sender's system -- but Gmail on the web, as well as many other sites, don't use the same header field. So you are quite right that the email client may display it with the false date. I have to admit, I experimented with this a bit last year, to see how different clients behaved. – Debra Sep 28 '13 at 23:51

Actually, the recipient need only look at the header to see when the email went through the servers. The Received and X-Received fields will show server date/time stamps, not the date/time on your computer. Since you don't own the mail servers involved, there's not much you can do about this (and if you did own all the servers involved, resetting the dates back would create all sorts of havoc.)

  • So if I would rent a cheap vserver, run only a minimal mail server on it and keep the time one day behind, then the "havoc" would be minimal wouldn't it? If I keep the same time on my sending computer, then the email wouldn't have no trace left of the real time and the recipient could be fooled completely (if offline for a day) – rubo77 Sep 27 '13 at 15:50
  • I don't know what havoc she refers to, but no they won't be fooled completely because virtual server or not, I suppose their POP server sticks a date on it when it receives it and you don't control that. They're only fooled if they don't check the headers. – barlop Sep 28 '13 at 22:38
  • The "havoc" that results when you try to manually reset a server back to a distant past time -- i.e. expired certificates and other functional issues. For example, it would be interesting to see what happens if a mail server, with an manual date setting some time in the past, would encounter in trying to send mail out when its certs are likely to show as expired. – Debra Sep 28 '13 at 23:47

I don't know for sure if this will work, as I haven't done it, but i've seen emails with the wrong date/time, and this is the way i'd think it happened technically, so this has a chance. If you set up your own smtp server with whatever date/time, that might do it, and cause the email program or web interface to use/see that date/time.

Email headers would give the prank away but it could work.

I have seen email with the wrong date/time, that includes wrong year.

There are other servers in the route, you can't set up the To person's POP server, and headers will give the prank away, if they check the headers.

But as i've seen emails with the wrong year, and it has been from either a spammer(with the wrong year) or emails with the wrong time, from an individual I know, and it hasn't been all emails, so I know it must've been something at their end, i.e. seems like it must be their SMTP server.

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