I sometimes spend a chunk of time (lets say 30 minutes) composing an email which, when I've checked it, I send. My next step is almost always to re-check the inbox. Occasionally I discover that whilst I was composing the email, the situation to which the email relates has moved on and the email I sent is now inaccurate.
The same word might also apply to a scientist who spends perhaps years doing research and then publishes, without checking that the assumptions his work is based on are still correct.
The upshot of the situation would be the need to issue a rapid update to the email/work to correct it.
UPDATE: Thanks for the answers so far. I think that 'obsolete' describes the situation that the work (or email) finds itself it. Could also be 'superceded'. Also liked E-moot.
However, I think that 'scooped' comes closest to what I was after. I'm really looking for a word which describes the experience of the person having done the work that is now obsolete (superceded or E-moot). As in "Jack was left feeling ?????? on realising his carefully constructed email was rendered obsolete by Tim's reply sent 5 minutes earlier".
Something that combines 'scooped' with 'deflated' might fit the bill.
It's probably adding to much to say that the feeling of deflatedness is caused in no small part by the knowledge that if less time had been spent on spelling, grammar and formatting, the work could have been sent/published whilst still relevant.
UPDATE 4/4/14: Got to say that "Ninja'd" comes closest to what I'm after. It combines the notion that I was beaten by someone with superior speed with the feeling of being phyiscally assaulted. If this does have a basis in internet culture then all the better. Nuts to the scientists. "Ninja'd" also addresses the 'too much time spent on formatting etc.' requirement since it suggests whoever Ninja'd me was possible more efficient or focussed.
Really enjoying this SE site - thanks everyone.