Definition
E-mail adulteration is a technique used in e-mail replies consisting in the partial change of the contents of an original e-mail message. It usually has the purpose of making fun, but can also be used for other malicious intents. This trick is most funny when applied to a message sent to an e-mail list.
E-mail adulteration is a writing technique intended to arouse surprise in the reader by changing the original content of an e-mail message in its reply and must not be confused with e-mail spoofing[1].
E-mail adulteration has been invented by Massanobu Tachikawa, a member of L.A.M.A. during the 1990s.
Examples
Example of original message:
|From:
John
|To:
[E-mail List]
|Subject:
Example
| |Hello guys, I'm in a good mood!
Example of reply (adulterated message):
|From:
Steve
|To:
[E-mail List]
|Subject:
Re: Example
| |Finally you accepted it! | | John wrote: | > Hello guys, I'm a good moron!
References
L.A.M.A. E-mail List (groups.google.com 
)
[1] E-mail spoofing is the forgery of an e-mail message header and usually but not necessarily its content.
"E-mail adulteration has been invented by Massanobu Tachikawa, a member of L.A.M.A. during the 1990s."
Nonsense. It's been a common gag since the inception of email.
Do you know who and when first used it? -- Josue
No, and there's no way to definitively answer that question. I recall seeing it since I started using Internet email and USENET in the late 80s, but mis-quoting an individual for comic or malicious effect is as old as the hills. It's hardly worth mentioning, especially as changing an email quote requires no more technical knowledge than how to move the cursor up or down the screen and apply a few keystrokes.
lol! You right! ;) It's hard to answer that question, but if some of our Internet elders recall some fragment of memory about that I would try to find an evidence or at least a story (myth?) for such creation. Remember that even the first use of smiles are documented. -- Josue
And some people just go all Grammar Vandal on the original message. Heck; sometimes I've been known to do that. And sometimes I wonder how often the original sender notices the changes.
-- Jeff Grigg
I fix grammar only in reply subject lines. I can't stand typos in the subject line repeat and repeat. And sometimes I fix typos in snippets I copy to comment. What else? I break the cited part and sometimes simplify it with "[...]". But I guess everybody does the latter two. -- Gunnar Zarncke
See original on c2.com