No, do not reply all. That is really bad advice. Reply to the email directly, and cc in your supervisor if you need to - don't air any more dirt laundry in public. Replying all and counter-arguing will not improve anyone's standing or repair any perceived loss of reputation - quite the opposite, and the rest of the people involved don't want to see it. Deal with it professionally, and privately.

@Thomo, that would be very good advice to the author of the initial email, before they sent it to everyone. Once they have already aired the dirty laundry, it's entirely appropriate to send a clarification email around to all the initial recipients informing them that the laundry is, in fact, not dirty. In a professionally worded way as in the answer. This is especially true if other department members were included in the email due to dependencies they themselves have on the departmental axolotls being fed.

I do agree that any follow-up after that - or anything other than a gentle factual correction - should be limited to direct participants and supervisors.

@Bruno - it would be. But you don't fight fire with fire. No-one wins from that. Keep it professional, respond direct and cc your supervisor. Anything else is just churlish

@Thomo I don't accept that my proposed response is "fighting fire with fire". There's a big difference between "you screwed up because you didn't do the thing, cc: all" and "this is the information I had, please clarify what you intended". For that matter, I don't agree that my proposed wording even constitutes "counter-arguing"; I took some pains to phrase it in a way that doesn't at any point assert that co-worker is incorrect.

Your acceptance is irrelevant. It's the difference between continuing drama and potentially developing a grievance, and handling it professionally and giving someone who potentially is having an off day to save some face. The fact that the first email was sent to everyone is irrelevant in how the response should be dealt with.

@Thomo that depends very much on the magnitude of the omission. If it's "you didn't wash up the teapot after lunch", sure, take it off line. If it's something like "you didn't do the safety checks", then letting that accusation stand may be severely damaging to OP's professional reputation, and it's important to reply. Giving people an opportunity to save face is a great idea, but maybe not when it's badly damaging to one's own. OP's post doesn't really give enough information to gauge whether the evil of letting the accusation stand outweighs the evil of reply-all.

@Thomo the fact that the original email is sent to everyone is exactly the reason why the reply needs to be sent to everyone. If you don't, everyone will only have the first mail to form an opinion off. There's nothing unprofessional about that. It's about protecting your reputation. I think if people humiliate other people publicly, then, if they're wrong, it needs to be set straight publicly, with the exact same visibility.

@PieterB Completely agree - the original sender should not have escalated this publicly. In doing so, they've opened themselves up to have the whole thing publicly responded to. While arguable advice, I'd possible even suggest calling that out in the response (depending on how ugly the original email is) "If you wish, we can discuss this further in private. I don't feel there is any need to involve the rest of the department."

@Thomo So your approach to incorrect claims that damage your reputation is to just shrug it off and leave several people with that negative impression, because hey who cares about their professional reputation at work?

@Thomo As soon as the other person CC's everyone in the email; it is no longer just a personal discussion between the two of you. They forfeit all right to have the problem corrected covertly. They could have done the exact same to you. If they think the issue is serious enough to go to multiple parties; your response should be as well. The other personal already decided what level the discussion was happening at.

I see not replying to all as a "he goes low, you go high" decision. In the past when things like this have happened to me, I have resisted the urge to reply all and instead reply only to the one person and my supervisor (not the other person's supervisor - that's my supervisor's job). To me, following the maxim of "praise in public, criticize in private" shows better leadership. Otherwise to me this is the best answer.

If this happened to me, I would be very professional about it and involve neither the others in the mail chain nor my immediate supervisors because I hate to air dirty laundry. Instead I would just don my stealth ninja dress, strap on my duel edged Katana and give him a visit and like @Thomo said "deal with it professionally, and privately."

Having fed the departmental axolotls on a few occasions, I can confirm that this is far from a simple task.

@Strawberry - it's easiest if you extend the food to them on an atlatl.

@DonBranson That's what I tried the last time; it's probably why I haven't been asked again.

@ToddWilcox If what you were doing were an attempt to undermine them, I would agree. In this case though, I don't think that's "low". They forced your hand into CCing everyone. This is not a decision you've made yourself to make them look bad. They decided that the information was relevant to everyone. If you think the information given to everyone is acceptable as is; then you don't need to respond. In this case though, OP thinks the information provided to everyone was incorrect. They already have incomplete information; it's not mean to keep them in the loop, it's effective.

@RobertGrant I guess I have a tendency to quickly develop a reputation for being effective and in my experience people who have tried to make blame fall on my head have had reputations for not being as effective. Also, when I've responded as I suggested in the past, in the cases where my supervisor has thought the politics would be served by clarifying what actually happened, they have sent out the e-mail saying that it wasn't actually my fault, which seems to come across much better than me defending myself. Also blaming someone else in front of everyone could undermine my supervisor.

@RobertGrant Depending on the situation, publicly blasting stuff could be the worst thing to do. If you're on a government contract (as I am now) and someone from yours or another contractor includes govvies in their e-mail blast and you reply all, it makes everyone look really bad. In those situations I don't even e-mail the original sender, I send all the supporting documents to my PM (supervisor) and let them handle the customer relationship - that's their job. My job is to execute and not do anything that makes us look bad. Blame gamers get fired sooner or later.

@JMac To put it as briefly as I can, I've learned over the years that disagreeing with someone in front of higher ups or customers or really anyone else besides that person and/or my supervisor just makes me look bad, regardless of whether I'm right or wrong. Just my experience.

@ToddWilcox Being publically shamed for not completing something also makes you look bad. It definitely depends on how you want to word it if you ask me. I know what you mean, email arguments can make you look bad. But so can rolling over and accepting crap people throw on you. It would depend to me how strongly the email to me was worded too. OP said they even included the email requesting the work done. They are trying to make it look like a serious slip up from OP. If the email were just "Looks like you forgot X so I did it." Would get a personal email from me...

... but the situation described seems more like a "wow look how bad they messed up I even have the email request here" email; where full self-defense should be pretty evident to anyone reading the chain.

@ToddWilcox "publically blasting" is not relevant as it really doesn't describe the answer's wording. And I don't see evidence that this is a contractor-customer relationship involving a project manager, so I don't think that's relevant either.

This answer is so incredibly diligent that it can be replied to all.

This. Stick to the facts, praise anything they did right, apologize if it turns out you were in the wrong, stay composed at all times, and let others form their own judgements.

Do not reply-to-all. That is a highly overused function that probably shouldn't have existed at all. There is no need to clear your "honor" in front of the other staff, they all just wish you two could shut up and not send them irrelevant mails. Don't troll your colleagues. Otherwise +1.