While it's true that the reply-all function serves a need, it's just as true that is often used thoughtlessly. Microsoft provides a free add-in for Outlook that lets you prevent recipients of certain messages from replying-all or forwarding.
Rob Lightner is a tech and gaming writer based in Seattle. He has reviewed games, gadgets, and technical manuals, written copy for space travel gear, and composed horoscopes for cats.
If you've never been a recipient of a mistaken reply-all, you're either very lucky or you don't use e-mail much.
It's a useful tool that is also one of the banes of our electronic lives, as well-meaning people blast dozens or hundreds of recipients with boring (or, worse, sensitive) replies that should be directed to one person. Microsoft has devised a free tool for Outlook that lets users create messages that keeps recipients on the same Exchange domain from using reply-all or forward. It's simple to use and doesn't require installation on the recipients' end. Here's how to use it.
Compose a new e-mail. You should see a few new buttons on the right side of the ribbon; these let you disable Reply-All, Forwarding, and even Reply to you. Click any one of them to disable that feature, but remember that it only works on recipients who are part of your Exchange domain.
The add-in also adds a new tab under Tools/Options. Use these to disable reply-all or forward on all new e-mails or to disable reply-all on messages you receive. If you feel sneaky, you could use that last feature on a reply-all recidivist's computer, but that might be more trouble than it's worth if you're not in the IT department.