I'm pretty sure that e-mail is from another player, not from the organizer, and he has somewhat misrepresented the situation there.
1) I did not cheat in the game, I followed all of the rules in the game and on their forum in general.
2) It is true that I did /out from the game on purpose, since it looked like that could give our team a significantly better chance of winning. This does not appear to be against any rules on their site, although they discourage people from /outing in general, with no mention as to what reasons for /outing are allowed and what aren't. My scumbuddy was an admin on the site, and I discussed the plan with him in the scum daychat before doing it, and although he did mention that it's not "good sportsmanship", he agreed that it would be beneficial for our team and did not attempt to stop me.
3) It is true that a mod of the game posted after the game to point out that my behavior was not acceptable. I could not have been reasonably expected to know that during the game, since it was not in the rules, and obviously if it had been in the rules, or the mods (who, to be fair, did not have access to the scum daychat) or my scumbuddy had informed me that quitting for strategic reasons is not acceptable on the forum, I would not have done it. In my message to the mods where I requested to /out, I did not claim to have any other motive for /outing besides the fact that I wasn't playing well enough. Apparently the mods assumed that it had something to do with people criticizing my playstyle, and subsequently sent out warnings to at least the person I believe this e-mail is from, but they made that assumption completely on their own and I most certainly did not try to mislead them into doing that.
4) It is not true that I would have been penalized with a temporary participation ban. In fact, I have not been penalized with a temporary participation ban as far as I can tell.
5) "Please do not use this (outing) as a manipulation technique" is obviously not a direct quote from any of our rules. He is referring to rule 3.9, and I have always understood the "this" in that rule to specifically refer to /outing in the main game thread, because that is what the entire rule is talking about. Whether or not we should reword that rule to make its intent more clear is up for debate.