---
title: "Coverage"
canonical: https://replypen.com/glossary/coverage
description: "Coverage is the share of incoming customer email that an AI tool handles at all, for example by writing a draft or an answer, out of all the email that needed a reply."
question: "What is coverage in AI customer support?"
author: "ReplyPen team"
published: 2026-09-30
operator: ProBackup BV (Hasselt, Belgium)
---

# What is coverage in AI customer support?

Coverage is the share of incoming customer email that an AI tool handles at all, for example by writing a draft or an answer, out of all the email that needed a reply. It tells you how much of the inbox the tool takes on, not how good its answers are.

The definition depends on what the tool does. For a drafting tool, coverage is usually emails with a
draft divided by emails that needed a reply. Emails deliberately skipped, such as newsletters and
notifications, belong in neither number.

## Why it matters

Coverage is half of the picture. High coverage with poor drafts means a lot of editing; low
coverage with excellent drafts means most of the inbox is still written by hand. Read it next to a
quality number such as the [sent-unchanged rate](https://replypen.com/glossary/sent-unchanged-rate.md).

It also shows gaps. If a whole kind of email never gets a draft, it may be filtered out by mistake,
or the tool may lack the sources to answer it.

## An example

Two hundred customer emails needed a reply this month and the tool drafted one for a hundred and
eighty. Coverage is nine in ten. The twenty without a draft were mostly questions in reply to an
old thread, which is worth looking into.

## Related

- [Sent-unchanged rate](https://replypen.com/glossary/sent-unchanged-rate.md): The sent-unchanged rate is the share of AI-written drafts sent to customers exactly as written, without a single edit.
- [Resolution rate](https://replypen.com/glossary/resolution-rate.md): A resolution rate is the share of customer conversations a support tool counts as resolved, often without a person getting involved.
- [Email triage](https://replypen.com/glossary/email-triage.md): Email triage is sorting incoming email before anyone answers it: deciding what needs a reply, what can wait, what goes to someone else and what needs no action at all.