|Photo by Gregg O'Connell on flickr|
Of course this backfires when others then use the Reply-All button after you do, and it's not long before you get the "explosion".
So here's a great way to limit the Reply-All Email Explosions, but like all things you do have to do a bit of work yourself. The trick is to use a targeted recipient list and then subsequently forward a separate copy of your message to a secondary list of people who "also need to know". If a member of either list uses Reply-All, they'll only hit other members of their own list, and not the other one.
As an example, suppose your report has to go to Alice, Bob and Claire for review and update, but you also need to copy in Dave, Ella and Frank so that they know that the report has been submitted. You could email all 6, but in the event of a Reply-All button hit by any of them, others will be spammed. Also, it might be better for Dave, Ella and Frank to not see the report until after the update phase, and comments at this time might be unhelpful.
Instead, you email Alice, Bob and Claire, attaching the report. Next, you go to your Sent Items folder, and forward a copy of the email you've just sent, to Dave, Ella and Frank, optionally removing the report if appropriate. Both groups now have the information they need, and any use of the Reply-All button will be limited to the groups themselves.
Of course, there's nothing to stop, for example, Ella emailing Alice, Bob and Claire and copying you in, but that's a process which requires a deliberate thought process rather than an automatic response to click a button.
Try it for yourself and see how well it works for you.