# What is double opt-in?

Double opt-in is a sign-up confirmed twice: the person enters their email address, then clicks a link in a confirmation email before they are added to the list. It proves the address works and that its owner asked to hear from you.

Updated 29 October 2026. Web page: https://chapbook.ink/glossary/double-opt-in/

## Why lists use it

Confirming keeps typos and other people's addresses off the list: every address on it works, and belongs to someone who asked to be there.

The cost is a step. Some people never click the confirmation link, so a double opt-in list grows more slowly than a single opt-in one.

## How it works with Chapbook

Chapbook collects sign-ups on a book's public page but sends no email of any kind to readers, confirmation included. Each sign-up lands in your Readers list marked unconfirmed. When you export the list and import it into your email tool, that tool can send its own confirmation, and your welcome sequence starts from there.

The sample on this page is a guide to that welcome sequence. Its chapter on the first email separates the confirmation, which is plumbing, from the first email a subscriber actually reads.

## Made with Chapbook: The Welcome Sequence

The Welcome Sequence: Seven emails that turn a subscriber into a reader, by Dana Okafor. Lead magnet, 3,626 words, 17 pages. A sample generated from one brief and exported unedited; it is not a customer's book. Read every page: https://chapbook.ink/examples/newsletter/

The brief:

> A seven-email welcome sequence for a new newsletter: what each email does, what to write, and when to send it. Promise: By the end you have a complete seven-email welcome sequence drafted, with a send schedule. Reader: Someone with fewer than a thousand subscribers who writes the newsletter themselves. Voice: Second person, warm and direct, worked examples with fictional newsletters, no invented open-rate statistics.

The outline the planner proposed:

1. Introduction (282 words)
2. Email 1: The one they actually open (681 words)
3. Emails 2 and 3: Who you are and what to expect (729 words)
4. Emails 4 and 5: Your best two pieces, reframed (669 words)
5. Emails 6 and 7: The ask, and the door left open (743 words)
6. The schedule and the template (478 words)

## Questions

### What is the difference between single and double opt-in?

Single opt-in adds an address to the list as soon as it is entered; double opt-in adds it only after its owner clicks a link in a confirmation email.

### Does Chapbook send a double opt-in email?

No. Chapbook never sends email to a reader. Sign-ups on a Chapbook book page arrive in your Readers list marked unconfirmed, and your email tool can send its own confirmation when you import them.