I’ve long known about the Reply-To header in emails but I’ve always been unclear on exactly what it did and how it worked. Karl Voit has an excellent short blog post on using the Reply-To header in emails. It turns out that it’s just what you need to solve a certain type of problem.
The use case that Voit describes is typical: you send an email to a group of people soliciting their opinion on some matter and say something like, “Please let Kate know what you think.” The problem is that almost everyone is simply going to hit reply and email you instead of Kate. The Reply-To header is the solution. By adding the header and specifying Kate’s email address, she instead of you will be emailed when the recipient hits reply.
Of course, that’s a simple use case. Voit describes some of the details of the header and the things you can do with it, including replying to multiple people. Take a look at Voit’s post. It’s a 5 minute read that’s very much worthwhile.