These tools sit between the incoming email and your reply. Some are built into the mail client and help when you ask; others watch an inbox and prepare a draft for every email that needs an answer. They differ mostly in what they know about your business and in whether they wait for you to send.
Why it matters
For a small business, most of the time spent on customer email goes into writing the same kinds of answers. A reply tool shifts the work from writing to checking. That only saves time if checking is fast, which depends on two things: whether the draft is grounded in your real policies and prices, and whether you can see what it was based on.
An example
A customer asks whether a product ships to Norway. The tool finds the shipping page on your website, writes a two-sentence reply with the delivery time it states, and leaves it in the thread. You read it, send it, and move on.
A longer explanation: what an AI email reply tool is and how one works.